diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index d41f6898e3..b7d088d87a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -13,6 +13,12 @@ repos:
       additional_dependencies: [isort==5.6.4]
     - id: nbqa-pyupgrade
       additional_dependencies: [pyupgrade==2.7.4]
+
+- repo: https://github.com/PyCQA/isort
+  rev: 5.6.4
+  hooks:
+    - id: isort
+      name: isort (python)
 - repo: https://github.com/asottile/pyupgrade
   rev: v2.7.4
   hooks:
diff --git a/benchmarks/benchmarks/benchmarks.py b/benchmarks/benchmarks/benchmarks.py
index 070c1bb66b..bbf8fbd5fc 100644
--- a/benchmarks/benchmarks/benchmarks.py
+++ b/benchmarks/benchmarks/benchmarks.py
@@ -17,10 +17,11 @@
 
 import numpy as np
 import pandas as pd
-import pymc3 as pm
 import theano
 import theano.tensor as tt
 
+import pymc3 as pm
+
 
 def glm_hierarchical_model(random_seed=123):
     """Sample glm hierarchical model to use in benchmarks"""
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 2d3743c01b..9b23a323af 100755
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -12,8 +12,8 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys
 import os
+import sys
 
 import pymc3
 
diff --git a/docs/source/sphinxext/gallery_generator.py b/docs/source/sphinxext/gallery_generator.py
index b3fdd23637..7023e1abcc 100644
--- a/docs/source/sphinxext/gallery_generator.py
+++ b/docs/source/sphinxext/gallery_generator.py
@@ -4,11 +4,11 @@
 Modified from the seaborn project, which modified the mpld3 project.
 """
 import base64
+import glob
 import json
 import os
-import glob
-import shutil
 import runpy
+import shutil
 
 import matplotlib
 
diff --git a/pymc3/__init__.py b/pymc3/__init__.py
index 1e913581b9..471eea3da7 100644
--- a/pymc3/__init__.py
+++ b/pymc3/__init__.py
@@ -38,38 +38,33 @@ def __set_compiler_flags():
 
 __set_compiler_flags()
 
+from . import gp, ode, sampling
+from .backends import load_trace, save_trace
+from .backends.tracetab import *
 from .blocking import *
+from .data import *
 from .distributions import *
 from .distributions import transforms
+from .exceptions import *
 from .glm import *
-from . import gp
 from .math import (
+    expand_packed_triangular,
+    invlogit,
+    invprobit,
     logaddexp,
-    logsumexp,
     logit,
-    invlogit,
-    expand_packed_triangular,
+    logsumexp,
     probit,
-    invprobit,
 )
 from .model import *
 from .model_graph import model_to_graphviz
-from . import ode
-from .stats import *
+from .plots import *
 from .sampling import *
-from .step_methods import *
 from .smc import *
+from .stats import *
+from .step_methods import *
+from .tests import test
 from .theanof import *
 from .tuning import *
 from .variational import *
 from .vartypes import *
-from .exceptions import *
-from . import sampling
-
-from .backends.tracetab import *
-from .backends import save_trace, load_trace
-
-from .plots import *
-from .tests import test
-
-from .data import *
diff --git a/pymc3/backends/__init__.py b/pymc3/backends/__init__.py
index 380d242633..d746b4408c 100644
--- a/pymc3/backends/__init__.py
+++ b/pymc3/backends/__init__.py
@@ -60,4 +60,4 @@
 Saved backends can be loaded using `arviz.from_netcdf`
 
 """
-from ..backends.ndarray import NDArray, save_trace, load_trace, point_list_to_multitrace
+from ..backends.ndarray import NDArray, load_trace, point_list_to_multitrace, save_trace
diff --git a/pymc3/backends/base.py b/pymc3/backends/base.py
index 2c57da6a5a..86bf4fb6f3 100644
--- a/pymc3/backends/base.py
+++ b/pymc3/backends/base.py
@@ -18,16 +18,17 @@
 """
 import itertools as itl
 import logging
-from typing import List
+import warnings
+
 from abc import ABC
+from typing import List
 
 import numpy as np
-import warnings
 import theano.tensor as tt
 
 from ..model import modelcontext
-from .report import SamplerReport, merge_reports
 from ..util import get_var_name
+from .report import SamplerReport, merge_reports
 
 logger = logging.getLogger("pymc3")
 
diff --git a/pymc3/backends/ndarray.py b/pymc3/backends/ndarray.py
index c2904dad1d..00bcf77692 100644
--- a/pymc3/backends/ndarray.py
+++ b/pymc3/backends/ndarray.py
@@ -20,14 +20,16 @@
 import json
 import os
 import shutil
-from typing import Optional, Dict, Any, List
 import warnings
 
+from typing import Any, Dict, List, Optional
+
 import numpy as np
+
 from pymc3.backends import base
 from pymc3.backends.base import MultiTrace
-from pymc3.model import Model, modelcontext
 from pymc3.exceptions import TraceDirectoryError
+from pymc3.model import Model, modelcontext
 
 
 def save_trace(trace: MultiTrace, directory: Optional[str] = None, overwrite=False) -> str:
diff --git a/pymc3/backends/report.py b/pymc3/backends/report.py
index 98937326da..5f4ffd3b47 100644
--- a/pymc3/backends/report.py
+++ b/pymc3/backends/report.py
@@ -12,15 +12,16 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import logging
-import enum
-from typing import Any, Optional
 import dataclasses
+import enum
+import logging
 
-from ..util import is_transformed_name, get_untransformed_name
+from typing import Any, Optional
 
 import arviz
 
+from ..util import get_untransformed_name, is_transformed_name
+
 logger = logging.getLogger("pymc3")
 
 
diff --git a/pymc3/backends/tracetab.py b/pymc3/backends/tracetab.py
index 0f9f750f16..ba7cbdaed1 100644
--- a/pymc3/backends/tracetab.py
+++ b/pymc3/backends/tracetab.py
@@ -15,9 +15,10 @@
 """Functions for converting traces into a table-like format
 """
 
+import warnings
+
 import numpy as np
 import pandas as pd
-import warnings
 
 from ..util import get_default_varnames
 
diff --git a/pymc3/blocking.py b/pymc3/blocking.py
index f951fb2bb7..c676197e43 100644
--- a/pymc3/blocking.py
+++ b/pymc3/blocking.py
@@ -17,9 +17,10 @@
 
 Classes for working with subsets of parameters.
 """
+import collections
 import copy
+
 import numpy as np
-import collections
 
 from .util import get_var_name
 
diff --git a/pymc3/data.py b/pymc3/data.py
index e1539a059f..78ab794c52 100644
--- a/pymc3/data.py
+++ b/pymc3/data.py
@@ -13,17 +13,19 @@
 #   limitations under the License.
 
 import collections
-from copy import copy
 import io
 import os
 import pkgutil
-from typing import Dict, List, Any
+
+from copy import copy
+from typing import Any, Dict, List
 
 import numpy as np
 import pandas as pd
-import pymc3 as pm
-import theano.tensor as tt
 import theano
+import theano.tensor as tt
+
+import pymc3 as pm
 
 __all__ = [
     "get_data",
diff --git a/pymc3/distributions/__init__.py b/pymc3/distributions/__init__.py
index b4b56d749a..7ae5d3b097 100644
--- a/pymc3/distributions/__init__.py
+++ b/pymc3/distributions/__init__.py
@@ -12,98 +12,93 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from . import timeseries
-from . import transforms
-from . import shape_utils
-
-from .posterior_predictive import fast_sample_posterior_predictive
-
-from .continuous import Uniform
-from .continuous import Flat
-from .continuous import HalfFlat
-from .continuous import TruncatedNormal
-from .continuous import Normal
-from .continuous import Beta
-from .continuous import Kumaraswamy
-from .continuous import Exponential
-from .continuous import Laplace
-from .continuous import StudentT
-from .continuous import Cauchy
-from .continuous import HalfCauchy
-from .continuous import Gamma
-from .continuous import Weibull
-from .continuous import HalfStudentT
-from .continuous import Lognormal
-from .continuous import ChiSquared
-from .continuous import HalfNormal
-from .continuous import Wald
-from .continuous import Pareto
-from .continuous import InverseGamma
-from .continuous import ExGaussian
-from .continuous import VonMises
-from .continuous import SkewNormal
-from .continuous import Triangular
-from .continuous import Gumbel
-from .continuous import Logistic
-from .continuous import LogitNormal
-from .continuous import Interpolated
-from .continuous import Rice
-from .continuous import Moyal
-
-from .discrete import Binomial
-from .discrete import BetaBinomial
-from .discrete import Bernoulli
-from .discrete import DiscreteWeibull
-from .discrete import Poisson
-from .discrete import NegativeBinomial
-from .discrete import ConstantDist
-from .discrete import Constant
-from .discrete import ZeroInflatedPoisson
-from .discrete import ZeroInflatedNegativeBinomial
-from .discrete import ZeroInflatedBinomial
-from .discrete import DiscreteUniform
-from .discrete import Geometric
-from .discrete import HyperGeometric
-from .discrete import Categorical
-from .discrete import OrderedLogistic
-
-from .distribution import DensityDist
-from .distribution import Distribution
-from .distribution import Continuous
-from .distribution import Discrete
-from .distribution import NoDistribution
-from .distribution import TensorType
-from .distribution import draw_values
-from .distribution import generate_samples
-
-from .simulator import Simulator
-
-from .mixture import Mixture
-from .mixture import NormalMixture
-from .mixture import MixtureSameFamily
-
-from .multivariate import MvNormal
-from .multivariate import MatrixNormal
-from .multivariate import KroneckerNormal
-from .multivariate import MvStudentT
-from .multivariate import Dirichlet
-from .multivariate import Multinomial
-from .multivariate import Wishart
-from .multivariate import WishartBartlett
-from .multivariate import LKJCholeskyCov
-from .multivariate import LKJCorr
-
-from .timeseries import AR1
-from .timeseries import AR
-from .timeseries import GaussianRandomWalk
-from .timeseries import GARCH11
-from .timeseries import MvGaussianRandomWalk
-from .timeseries import MvStudentTRandomWalk
-
+from . import shape_utils, timeseries, transforms
 from .bart import BART
-
 from .bound import Bound
-
+from .continuous import (
+    Beta,
+    Cauchy,
+    ChiSquared,
+    ExGaussian,
+    Exponential,
+    Flat,
+    Gamma,
+    Gumbel,
+    HalfCauchy,
+    HalfFlat,
+    HalfNormal,
+    HalfStudentT,
+    Interpolated,
+    InverseGamma,
+    Kumaraswamy,
+    Laplace,
+    Logistic,
+    LogitNormal,
+    Lognormal,
+    Moyal,
+    Normal,
+    Pareto,
+    Rice,
+    SkewNormal,
+    StudentT,
+    Triangular,
+    TruncatedNormal,
+    Uniform,
+    VonMises,
+    Wald,
+    Weibull,
+)
+from .discrete import (
+    Bernoulli,
+    BetaBinomial,
+    Binomial,
+    Categorical,
+    Constant,
+    ConstantDist,
+    DiscreteUniform,
+    DiscreteWeibull,
+    Geometric,
+    HyperGeometric,
+    NegativeBinomial,
+    OrderedLogistic,
+    Poisson,
+    ZeroInflatedBinomial,
+    ZeroInflatedNegativeBinomial,
+    ZeroInflatedPoisson,
+)
+from .distribution import (
+    Continuous,
+    DensityDist,
+    Discrete,
+    Distribution,
+    NoDistribution,
+    TensorType,
+    draw_values,
+    generate_samples,
+)
+from .mixture import Mixture, MixtureSameFamily, NormalMixture
+from .multivariate import (
+    Dirichlet,
+    KroneckerNormal,
+    LKJCholeskyCov,
+    LKJCorr,
+    MatrixNormal,
+    Multinomial,
+    MvNormal,
+    MvStudentT,
+    Wishart,
+    WishartBartlett,
+)
+from .posterior_predictive import fast_sample_posterior_predictive
+from .simulator import Simulator
+from .timeseries import (
+    AR,
+    AR1,
+    GARCH11,
+    GaussianRandomWalk,
+    MvGaussianRandomWalk,
+    MvStudentTRandomWalk,
+)
 
 __all__ = [
     "Uniform",
diff --git a/pymc3/distributions/bart.py b/pymc3/distributions/bart.py
index c512d84576..19b677c347 100644
--- a/pymc3/distributions/bart.py
+++ b/pymc3/distributions/bart.py
@@ -13,8 +13,9 @@
 #   limitations under the License.
 
 import numpy as np
+
 from .distribution import NoDistribution
-from .tree import Tree, SplitNode, LeafNode
+from .tree import LeafNode, SplitNode, Tree
 
 __all__ = ["BART"]
 
diff --git a/pymc3/distributions/bound.py b/pymc3/distributions/bound.py
index bde9abc887..074a575eba 100644
--- a/pymc3/distributions/bound.py
+++ b/pymc3/distributions/bound.py
@@ -17,16 +17,15 @@
 import numpy as np
 import theano.tensor as tt
 
+from pymc3.distributions import transforms
+from pymc3.distributions.dist_math import bound
 from pymc3.distributions.distribution import (
-    Distribution,
-    Discrete,
     Continuous,
+    Discrete,
+    Distribution,
     draw_values,
     generate_samples,
 )
-from pymc3.distributions import transforms
-from pymc3.distributions.dist_math import bound
-
 from pymc3.theanof import floatX
 
 __all__ = ["Bound"]
diff --git a/pymc3/distributions/continuous.py b/pymc3/distributions/continuous.py
index 533aeff5b4..dd8a82bdf7 100644
--- a/pymc3/distributions/continuous.py
+++ b/pymc3/distributions/continuous.py
@@ -23,30 +23,31 @@
 import theano
 import theano.tensor as tt
 
+from scipy import stats
+from scipy.interpolate import InterpolatedUnivariateSpline
+from scipy.special import expit
+
+from pymc3.theanof import floatX
+
+from ..math import invlogit, logdiffexp, logit
 from . import transforms
 from .dist_math import (
+    SplineWrapper,
     alltrue_elemwise,
     betaln,
     bound,
+    clipped_beta_rvs,
     gammaln,
     i0e,
     incomplete_beta,
     logpow,
     normal_lccdf,
     normal_lcdf,
-    SplineWrapper,
     std_cdf,
     zvalue,
-    clipped_beta_rvs,
 )
 from .distribution import Continuous, draw_values, generate_samples
 from .special import log_i0
-from ..math import invlogit, logit, logdiffexp
-
-from pymc3.theanof import floatX
-from scipy import stats
-from scipy.special import expit
-from scipy.interpolate import InterpolatedUnivariateSpline
 
 __all__ = [
     "Uniform",
diff --git a/pymc3/distributions/discrete.py b/pymc3/distributions/discrete.py
index d88c9bcd21..8a6f9f7989 100644
--- a/pymc3/distributions/discrete.py
+++ b/pymc3/distributions/discrete.py
@@ -12,17 +12,19 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import warnings
+
 import numpy as np
 import theano.tensor as tt
+
 from scipy import stats
-import warnings
 
-from .dist_math import bound, factln, binomln, betaln, logpow, random_choice
+from pymc3.math import log1pexp, logaddexp, logit, sigmoid, tround
+
+from ..theanof import floatX, intX, take_along_axis
+from .dist_math import betaln, binomln, bound, factln, logpow, random_choice
 from .distribution import Discrete, draw_values, generate_samples
 from .shape_utils import broadcast_distribution_samples
-from pymc3.math import tround, sigmoid, logaddexp, logit, log1pexp
-from ..theanof import floatX, intX, take_along_axis
-
 
 __all__ = [
     "Binomial",
diff --git a/pymc3/distributions/dist_math.py b/pymc3/distributions/dist_math.py
index 1af8e86c72..b4ea71a837 100644
--- a/pymc3/distributions/dist_math.py
+++ b/pymc3/distributions/dist_math.py
@@ -18,21 +18,23 @@
 @author: johnsalvatier
 """
 import platform
+
 import numpy as np
 import scipy.linalg
 import scipy.stats
-import theano.tensor as tt
 import theano
-from theano.scalar import UnaryScalarOp, upgrade_to_float_no_complex
-from theano.tensor.slinalg import Cholesky
+import theano.tensor as tt
+
+from theano import scan
 from theano.compile.builders import OpFromGraph
+from theano.scalar import UnaryScalarOp, upgrade_to_float_no_complex
 from theano.scan import until
-from theano import scan
-from .shape_utils import to_tuple
+from theano.tensor.slinalg import Cholesky
 
-from .special import gammaln
 from pymc3.theanof import floatX
 
+from .shape_utils import to_tuple
+from .special import gammaln
 
 f = floatX
 c = -0.5 * np.log(2.0 * np.pi)
diff --git a/pymc3/distributions/distribution.py b/pymc3/distributions/distribution.py
index c8c895c188..062ceb00cd 100644
--- a/pymc3/distributions/distribution.py
+++ b/pymc3/distributions/distribution.py
@@ -12,31 +12,42 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import multiprocessing
-import numbers
 import contextvars
-import dill
 import inspect
+import multiprocessing
+import numbers
 import sys
 import types
-from typing import TYPE_CHECKING
 import warnings
 
+from typing import TYPE_CHECKING
+
+import dill
+
 if TYPE_CHECKING:
     from typing import Optional, Callable
 
 import numpy as np
+import theano
 import theano.tensor as tt
+
 from theano import function
-from ..util import get_repr_for_variable, get_var_name
-import theano
+
 from ..memoize import memoize
-from ..model import Model, build_named_node_tree, FreeRV, ObservedRV, MultiObservedRV, ContextMeta
+from ..model import (
+    ContextMeta,
+    FreeRV,
+    Model,
+    MultiObservedRV,
+    ObservedRV,
+    build_named_node_tree,
+)
+from ..util import get_repr_for_variable, get_var_name
 from ..vartypes import string_types, theano_constant
 from .shape_utils import (
-    to_tuple,
-    get_broadcastable_dist_samples,
     broadcast_dist_samples_shape,
+    get_broadcastable_dist_samples,
+    to_tuple,
 )
 
 __all__ = [
diff --git a/pymc3/distributions/mixture.py b/pymc3/distributions/mixture.py
index dcfd823fa1..794ae82322 100644
--- a/pymc3/distributions/mixture.py
+++ b/pymc3/distributions/mixture.py
@@ -12,29 +12,31 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import warnings
+
 from collections.abc import Iterable
+
 import numpy as np
 import theano
 import theano.tensor as tt
-import warnings
 
 from ..math import logsumexp
+from ..theanof import _conversion_map, take_along_axis
+from .continuous import Normal, get_tau_sigma
 from .dist_math import bound, random_choice
 from .distribution import (
     Discrete,
     Distribution,
-    draw_values,
-    generate_samples,
     _DrawValuesContext,
     _DrawValuesContextBlocker,
+    draw_values,
+    generate_samples,
 )
 from .shape_utils import (
-    to_tuple,
     broadcast_distribution_samples,
     get_broadcastable_dist_samples,
+    to_tuple,
 )
-from .continuous import get_tau_sigma, Normal
-from ..theanof import _conversion_map, take_along_axis
 
 __all__ = ["Mixture", "NormalMixture", "MixtureSameFamily"]
 
diff --git a/pymc3/distributions/multivariate.py b/pymc3/distributions/multivariate.py
index 2d4c433d28..67780891b5 100755
--- a/pymc3/distributions/multivariate.py
+++ b/pymc3/distributions/multivariate.py
@@ -16,29 +16,36 @@
 # -*- coding: utf-8 -*-
 
 import warnings
+
 import numpy as np
 import scipy
 import theano
 import theano.tensor as tt
 
-from scipy import stats, linalg
-
+from scipy import linalg, stats
 from theano.gof.op import get_test_value
 from theano.gof.utils import TestValueError
-from theano.tensor.nlinalg import det, matrix_inverse, trace, eigh
+from theano.tensor.nlinalg import det, eigh, matrix_inverse, trace
 from theano.tensor.slinalg import Cholesky
+
 import pymc3 as pm
 
 from pymc3.theanof import floatX
-from . import transforms
-from .distribution import Continuous, Discrete, draw_values, generate_samples, _DrawValuesContext
+
+from ..math import kron_diag, kron_dot, kron_solve_lower, kronecker
 from ..model import Deterministic
+from . import transforms
 from .continuous import ChiSquared, Normal
+from .dist_math import bound, factln, logpow
+from .distribution import (
+    Continuous,
+    Discrete,
+    _DrawValuesContext,
+    draw_values,
+    generate_samples,
+)
+from .shape_utils import broadcast_dist_samples_to, to_tuple
 from .special import gammaln, multigammaln
-from .dist_math import bound, logpow, factln
-from .shape_utils import to_tuple, broadcast_dist_samples_to
-from ..math import kron_dot, kron_diag, kron_solve_lower, kronecker
-
 
 __all__ = [
     "MvNormal",
diff --git a/pymc3/distributions/posterior_predictive.py b/pymc3/distributions/posterior_predictive.py
index 8efec54af7..f3d6e4f591 100644
--- a/pymc3/distributions/posterior_predictive.py
+++ b/pymc3/distributions/posterior_predictive.py
@@ -1,48 +1,50 @@
+import contextvars
+import logging
 import numbers
+import warnings
+
+from collections import UserDict
+from contextlib import AbstractContextManager
 from typing import (
-    List,
-    Dict,
+    TYPE_CHECKING,
     Any,
+    Callable,
+    Dict,
+    List,
     Optional,
+    Set,
     Tuple,
     Union,
     cast,
-    TYPE_CHECKING,
-    Callable,
     overload,
-    Set,
 )
-import warnings
-import logging
-from collections import UserDict
-from contextlib import AbstractContextManager
-import contextvars
-from typing_extensions import Protocol, Literal
 
 import numpy as np
 import theano
 import theano.tensor as tt
-from xarray import Dataset
+
 from arviz import InferenceData
+from typing_extensions import Literal, Protocol
+from xarray import Dataset
 
 from ..backends.base import MultiTrace
-from .distribution import (
-    _DrawValuesContext,
-    _DrawValuesContextBlocker,
-    is_fast_drawable,
-    _compile_theano_function,
-    vectorized_ppc,
-)
+from ..exceptions import IncorrectArgumentsError
 from ..model import (
     Model,
-    get_named_nodes_and_relations,
-    ObservedRV,
     MultiObservedRV,
+    ObservedRV,
+    get_named_nodes_and_relations,
     modelcontext,
 )
-from ..exceptions import IncorrectArgumentsError
+from ..util import chains_and_samples, dataset_to_point_list, get_var_name
 from ..vartypes import theano_constant
-from ..util import dataset_to_point_list, chains_and_samples, get_var_name
+from .distribution import (
+    _compile_theano_function,
+    _DrawValuesContext,
+    _DrawValuesContextBlocker,
+    is_fast_drawable,
+    vectorized_ppc,
+)
 
 # Failing tests:
 #    test_mixture_random_shape::test_mixture_random_shape
diff --git a/pymc3/distributions/shape_utils.py b/pymc3/distributions/shape_utils.py
index c41507620f..a339ae7c08 100644
--- a/pymc3/distributions/shape_utils.py
+++ b/pymc3/distributions/shape_utils.py
@@ -19,7 +19,6 @@
 """
 import numpy as np
 
-
 __all__ = [
     "to_tuple",
     "shapes_broadcasting",
diff --git a/pymc3/distributions/simulator.py b/pymc3/distributions/simulator.py
index 2662c86679..3a70538f03 100644
--- a/pymc3/distributions/simulator.py
+++ b/pymc3/distributions/simulator.py
@@ -13,10 +13,13 @@
 #   limitations under the License.
 
 import logging
+
 import numpy as np
-from .distribution import NoDistribution, draw_values
+
 from scipy.spatial import cKDTree
 
+from .distribution import NoDistribution, draw_values
+
 __all__ = ["Simulator"]
 
 _log = logging.getLogger("pymc3")
diff --git a/pymc3/distributions/special.py b/pymc3/distributions/special.py
index 1401596486..ba4662b2df 100644
--- a/pymc3/distributions/special.py
+++ b/pymc3/distributions/special.py
@@ -14,8 +14,9 @@
 
 import numpy as np
 import theano.tensor as tt
-from theano.scalar.basic_scipy import GammaLn, Psi
+
 from theano import scalar
+from theano.scalar.basic_scipy import GammaLn, Psi
 
 __all__ = ["gammaln", "multigammaln", "psi", "log_i0"]
 
diff --git a/pymc3/distributions/timeseries.py b/pymc3/distributions/timeseries.py
index ab637cd547..09fe6c41cf 100644
--- a/pymc3/distributions/timeseries.py
+++ b/pymc3/distributions/timeseries.py
@@ -14,16 +14,15 @@
 
 import warnings
 
-from scipy import stats
+import numpy as np
 import theano.tensor as tt
+
+from scipy import stats
 from theano import scan
-import numpy as np
 
-from .continuous import get_tau_sigma, Normal, Flat
+from . import distribution, multivariate
+from .continuous import Flat, Normal, get_tau_sigma
 from .shape_utils import to_tuple
-from . import multivariate
-from . import distribution
-
 
 __all__ = [
     "AR1",
diff --git a/pymc3/distributions/transforms.py b/pymc3/distributions/transforms.py
index 92a38178ec..c912a648b0 100644
--- a/pymc3/distributions/transforms.py
+++ b/pymc3/distributions/transforms.py
@@ -13,16 +13,17 @@
 #   limitations under the License.
 
 import warnings
+
+import numpy as np
 import theano.tensor as tt
 
+from scipy.special import logit as nplogit
+
+from ..math import invlogit, logit, logsumexp
 from ..model import FreeRV
-from ..theanof import gradient, floatX
+from ..theanof import floatX, gradient
 from . import distribution
-from ..math import logit, invlogit, logsumexp
 from .distribution import draw_values
-import numpy as np
-from scipy.special import logit as nplogit
-
 
 __all__ = [
     "Transform",
diff --git a/pymc3/distributions/tree.py b/pymc3/distributions/tree.py
index 3b2c098e89..81c727232a 100644
--- a/pymc3/distributions/tree.py
+++ b/pymc3/distributions/tree.py
@@ -12,10 +12,12 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import numpy as np
 import math
+
 from copy import deepcopy
 
+import numpy as np
+
 
 class Tree:
     """Full binary tree
diff --git a/pymc3/examples/GHME_2013.py b/pymc3/examples/GHME_2013.py
index a9176c50ca..ef08df1f17 100644
--- a/pymc3/examples/GHME_2013.py
+++ b/pymc3/examples/GHME_2013.py
@@ -1,6 +1,6 @@
+import matplotlib.pyplot as plt
 import numpy as np
 import pandas as pd
-import matplotlib.pyplot as plt
 
 from pymc3 import HalfCauchy, Model, Normal, get_data, sample
 from pymc3.distributions.timeseries import GaussianRandomWalk
diff --git a/pymc3/examples/LKJ_correlation.py b/pymc3/examples/LKJ_correlation.py
index ec3f87288d..8a70c38a65 100644
--- a/pymc3/examples/LKJ_correlation.py
+++ b/pymc3/examples/LKJ_correlation.py
@@ -1,6 +1,8 @@
-import theano.tensor as tt
 import numpy as np
+import theano.tensor as tt
+
 from numpy.random import multivariate_normal
+
 import pymc3 as pm
 
 # Generate some multivariate normal data:
diff --git a/pymc3/examples/arbitrary_stochastic.py b/pymc3/examples/arbitrary_stochastic.py
index 87850347be..1840e11612 100644
--- a/pymc3/examples/arbitrary_stochastic.py
+++ b/pymc3/examples/arbitrary_stochastic.py
@@ -1,7 +1,8 @@
 import numpy as np
-import pymc3 as pm
 import theano.tensor as tt
 
+import pymc3 as pm
+
 
 # custom log-liklihood
 def logp(failure, lam, value):
diff --git a/pymc3/examples/arma_example.py b/pymc3/examples/arma_example.py
index c5a26177ac..c183052256 100644
--- a/pymc3/examples/arma_example.py
+++ b/pymc3/examples/arma_example.py
@@ -1,7 +1,8 @@
-import pymc3 as pm
+import numpy as np
+
 from theano import scan, shared
 
-import numpy as np
+import pymc3 as pm
 
 """
 ARMA example
diff --git a/pymc3/examples/baseball.py b/pymc3/examples/baseball.py
index 50e891c054..f861099a7f 100644
--- a/pymc3/examples/baseball.py
+++ b/pymc3/examples/baseball.py
@@ -3,9 +3,10 @@
 # See http://mc-stan.org/documentation/case-studies/pool-binary-trials.html for more details
 #
 
-import pymc3 as pm
 import numpy as np
 
+import pymc3 as pm
+
 
 def build_model():
     data = np.loadtxt(
diff --git a/pymc3/examples/custom_dists.py b/pymc3/examples/custom_dists.py
index a9789bab9d..fb7605265e 100644
--- a/pymc3/examples/custom_dists.py
+++ b/pymc3/examples/custom_dists.py
@@ -10,9 +10,9 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
+import theano.tensor as tt
 
 import pymc3 as pm
-import theano.tensor as tt
 
 np.random.seed(42)
 theta_true = (25, 0.5)
diff --git a/pymc3/examples/disaster_model.py b/pymc3/examples/disaster_model.py
index f0459bc161..103206a6d7 100644
--- a/pymc3/examples/disaster_model.py
+++ b/pymc3/examples/disaster_model.py
@@ -9,10 +9,11 @@
 """
 
 
-import pymc3 as pm
 import theano.tensor as tt
+
 from numpy import arange, array
 
+import pymc3 as pm
 
 __all__ = ["disasters_data", "switchpoint", "early_mean", "late_mean", "rate", "disasters"]
 
diff --git a/pymc3/examples/disaster_model_theano_op.py b/pymc3/examples/disaster_model_theano_op.py
index b8c2b4c7de..3b3597a287 100644
--- a/pymc3/examples/disaster_model_theano_op.py
+++ b/pymc3/examples/disaster_model_theano_op.py
@@ -5,10 +5,12 @@
 """
 
 
-import pymc3 as pm
-from theano.compile.ops import as_op
 import theano.tensor as tt
+
 from numpy import arange, array, empty
+from theano.compile.ops import as_op
+
+import pymc3 as pm
 
 __all__ = ["disasters_data", "switchpoint", "early_mean", "late_mean", "rate", "disasters"]
 
diff --git a/pymc3/examples/garch_example.py b/pymc3/examples/garch_example.py
index 33744ed132..bf22955512 100644
--- a/pymc3/examples/garch_example.py
+++ b/pymc3/examples/garch_example.py
@@ -1,6 +1,7 @@
-from pymc3 import Normal, sample, Model, Uniform, summary
-import theano.tensor as tt
 import numpy as np
+import theano.tensor as tt
+
+from pymc3 import Model, Normal, Uniform, sample, summary
 
 """
 Example from Stan - slightly altered
diff --git a/pymc3/examples/gelman_bioassay.py b/pymc3/examples/gelman_bioassay.py
index 6fca8bc468..032080755e 100644
--- a/pymc3/examples/gelman_bioassay.py
+++ b/pymc3/examples/gelman_bioassay.py
@@ -1,5 +1,6 @@
+from numpy import array, ones
+
 import pymc3 as pm
-from numpy import ones, array
 
 # Samples for each dose level
 n = 5 * ones(4, dtype=int)
diff --git a/pymc3/examples/gelman_schools.py b/pymc3/examples/gelman_schools.py
index ef023c2096..984f305875 100644
--- a/pymc3/examples/gelman_schools.py
+++ b/pymc3/examples/gelman_schools.py
@@ -1,6 +1,7 @@
-from pymc3 import HalfCauchy, Normal, sample, Model, loo
 import numpy as np
 
+from pymc3 import HalfCauchy, Model, Normal, loo, sample
+
 """Original Stan model
 
 data {
diff --git a/pymc3/examples/lasso_missing.py b/pymc3/examples/lasso_missing.py
index 2ce3192af0..1757811edb 100644
--- a/pymc3/examples/lasso_missing.py
+++ b/pymc3/examples/lasso_missing.py
@@ -1,7 +1,9 @@
-import pymc3 as pm
 import pandas as pd
+
 from numpy.ma import masked_values
 
+import pymc3 as pm
+
 # Import data, filling missing values with sentinels (-999)
 test_scores = pd.read_csv(pm.get_data("test_scores.csv")).fillna(-999)
 
diff --git a/pymc3/examples/lightspeed_example.py b/pymc3/examples/lightspeed_example.py
index 7dc76bb225..8edfea5961 100644
--- a/pymc3/examples/lightspeed_example.py
+++ b/pymc3/examples/lightspeed_example.py
@@ -1,4 +1,5 @@
 import numpy as np
+
 import pymc3 as pm
 
 light_speed = np.array(
diff --git a/pymc3/examples/rankdata_ordered.py b/pymc3/examples/rankdata_ordered.py
index cea237e140..ef5a0f5fae 100644
--- a/pymc3/examples/rankdata_ordered.py
+++ b/pymc3/examples/rankdata_ordered.py
@@ -1,7 +1,8 @@
 import numpy as np
-import pymc3 as pm
 import theano.tensor as tt
 
+import pymc3 as pm
+
 """
 Using Ordered transformation to model ranking data
 inspired by the Stan implementation of Thurstonian model
diff --git a/pymc3/examples/samplers_mvnormal.py b/pymc3/examples/samplers_mvnormal.py
index 54db0f9146..2d5fb1a8ab 100644
--- a/pymc3/examples/samplers_mvnormal.py
+++ b/pymc3/examples/samplers_mvnormal.py
@@ -7,12 +7,14 @@
 """
 
 
-import numpy as np
 import time
+
+import numpy as np
 import pandas as pd
-import pymc3 as pm
 import theano.tensor as tt
 
+import pymc3 as pm
+
 # with this flag one can switch between defining the bivariate normal as
 # either a 2D MvNormal (USE_XY = False) split up the two dimensions into
 # two variables 'x' and 'y'.  The latter is recommended because it highlights
diff --git a/pymc3/examples/simpletest.py b/pymc3/examples/simpletest.py
index c54c76a856..32c658eb42 100644
--- a/pymc3/examples/simpletest.py
+++ b/pymc3/examples/simpletest.py
@@ -1,6 +1,7 @@
-import pymc3 as pm
 import numpy as np
 
+import pymc3 as pm
+
 # import pydevd
 # pydevd.set_pm_excepthook()
 np.seterr(invalid="raise")
diff --git a/pymc3/glm/__init__.py b/pymc3/glm/__init__.py
index 6c1b75acbf..762538075e 100644
--- a/pymc3/glm/__init__.py
+++ b/pymc3/glm/__init__.py
@@ -12,5 +12,5 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from .linear import LinearComponent, GLM
 from . import families
+from .linear import GLM, LinearComponent
diff --git a/pymc3/glm/families.py b/pymc3/glm/families.py
index 1fd10f0418..814cb2e5fa 100644
--- a/pymc3/glm/families.py
+++ b/pymc3/glm/families.py
@@ -13,12 +13,14 @@
 #   limitations under the License.
 
 import numbers
-import numpy as np
+
 from copy import copy
 
+import numpy as np
 import theano.tensor as tt
-from ..model import modelcontext
+
 from .. import distributions as pm_dists
+from ..model import modelcontext
 
 __all__ = ["Normal", "StudentT", "Binomial", "Poisson", "NegativeBinomial"]
 
diff --git a/pymc3/glm/linear.py b/pymc3/glm/linear.py
index 71b20652cf..3529d96776 100644
--- a/pymc3/glm/linear.py
+++ b/pymc3/glm/linear.py
@@ -12,14 +12,14 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import theano.tensor as tt
 import numpy as np
-from ..distributions import Normal, Flat
+import theano.tensor as tt
+
+from ..distributions import Flat, Normal
+from ..model import Deterministic, Model
 from . import families
-from ..model import Model, Deterministic
 from .utils import any_to_tensor_and_labels
 
-
 __all__ = ["LinearComponent", "GLM"]
 
 
diff --git a/pymc3/glm/utils.py b/pymc3/glm/utils.py
index d36b8ecc62..889284b317 100644
--- a/pymc3/glm/utils.py
+++ b/pymc3/glm/utils.py
@@ -12,8 +12,8 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pandas as pd
 import numpy as np
+import pandas as pd
 import theano.tensor as tt
 
 
diff --git a/pymc3/gp/__init__.py b/pymc3/gp/__init__.py
index a39f7fe93f..8704266ab8 100644
--- a/pymc3/gp/__init__.py
+++ b/pymc3/gp/__init__.py
@@ -12,7 +12,5 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from . import cov
-from . import mean
-from . import util
-from .gp import Latent, Marginal, MarginalSparse, TP, LatentKron, MarginalKron
+from . import cov, mean, util
+from .gp import TP, Latent, LatentKron, Marginal, MarginalKron, MarginalSparse
diff --git a/pymc3/gp/cov.py b/pymc3/gp/cov.py
index 69d1c2f410..7a01a9eec5 100644
--- a/pymc3/gp/cov.py
+++ b/pymc3/gp/cov.py
@@ -13,12 +13,14 @@
 #   limitations under the License.
 
 import warnings
+
+from functools import reduce
+from numbers import Number
+from operator import add, mul
+
 import numpy as np
 import theano
 import theano.tensor as tt
-from functools import reduce
-from operator import mul, add
-from numbers import Number
 
 __all__ = [
     "Constant",
diff --git a/pymc3/gp/gp.py b/pymc3/gp/gp.py
index aa2e2f058e..92aceb24f4 100644
--- a/pymc3/gp/gp.py
+++ b/pymc3/gp/gp.py
@@ -18,20 +18,23 @@
 import numpy as np
 import theano.tensor as tt
 
+from theano.tensor.nlinalg import eigh
+
 import pymc3 as pm
-from pymc3.gp.cov import Covariance, Constant
+
+from pymc3.distributions import draw_values
+from pymc3.gp.cov import Constant, Covariance
 from pymc3.gp.mean import Zero
 from pymc3.gp.util import (
+    cholesky,
     conditioned_vars,
     infer_shape,
-    stabilize,
-    cholesky,
     solve_lower,
     solve_upper,
+    stabilize,
 )
-from pymc3.distributions import draw_values
-from theano.tensor.nlinalg import eigh
-from ..math import cartesian, kron_dot, kron_diag, kron_solve_lower, kron_solve_upper
+
+from ..math import cartesian, kron_diag, kron_dot, kron_solve_lower, kron_solve_upper
 
 __all__ = ["Latent", "Marginal", "TP", "MarginalSparse", "LatentKron", "MarginalKron"]
 
diff --git a/pymc3/gp/util.py b/pymc3/gp/util.py
index b35ffeac48..698c300564 100644
--- a/pymc3/gp/util.py
+++ b/pymc3/gp/util.py
@@ -12,10 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from scipy.cluster.vq import kmeans
+import warnings
+
 import numpy as np
 import theano.tensor as tt
-import warnings
+import theano.tensor.slinalg  # pylint: disable=unused-import
+
+from scipy.cluster.vq import kmeans
 
 cholesky = tt.slinalg.cholesky
 solve_lower = tt.slinalg.Solve(A_structure="lower_triangular")
diff --git a/pymc3/math.py b/pymc3/math.py
index dba3f938a6..bba098678a 100644
--- a/pymc3/math.py
+++ b/pymc3/math.py
@@ -13,63 +13,67 @@
 #   limitations under the License.
 
 import sys
+
+from functools import partial, reduce
+
+import numpy as np
+import scipy as sp
+import scipy.sparse  # pylint: disable=unused-import
+import theano
+import theano.sparse
 import theano.tensor as tt
+import theano.tensor.slinalg  # pylint: disable=unused-import
+
+from scipy.linalg import block_diag as scipy_block_diag
+from theano.gof import Apply, Op
 
 # pylint: disable=unused-import
-import theano
 from theano.tensor import (
+    abs_,
+    and_,
+    ceil,
+    clip,
+    concatenate,
     constant,
+    cos,
+    cosh,
+    dot,
+    eq,
+    erf,
+    erfc,
+    erfcinv,
+    erfinv,
+    exp,
     flatten,
-    zeros_like,
-    ones_like,
-    stack,
-    concatenate,
-    sum,
-    prod,
-    lt,
+    floor,
+    ge,
     gt,
     le,
-    ge,
-    eq,
+    log,
+    lt,
+    maximum,
+    minimum,
     neq,
-    switch,
-    clip,
-    where,
-    and_,
+    ones_like,
     or_,
-    abs_,
-    exp,
-    log,
-    cos,
+    prod,
+    sgn,
     sin,
-    tan,
-    cosh,
     sinh,
-    tanh,
     sqr,
     sqrt,
-    erf,
-    erfc,
-    erfinv,
-    erfcinv,
-    dot,
-    maximum,
-    minimum,
-    sgn,
-    ceil,
-    floor,
+    stack,
+    sum,
+    switch,
+    tan,
+    tanh,
+    where,
+    zeros_like,
 )
-from theano.tensor.nlinalg import det, matrix_inverse, extract_diag, matrix_dot, trace
-import theano.tensor.slinalg
-import theano.sparse
+from theano.tensor.nlinalg import det, extract_diag, matrix_dot, matrix_inverse, trace
 from theano.tensor.nnet import sigmoid
-from theano.gof import Op, Apply
-import numpy as np
-import scipy as sp
-import scipy.sparse
-from scipy.linalg import block_diag as scipy_block_diag
-from pymc3.theanof import floatX, largest_common_dtype, ix_
-from functools import reduce, partial
+
+from pymc3.theanof import floatX, ix_, largest_common_dtype
 
 # pylint: enable=unused-import
 
diff --git a/pymc3/memoize.py b/pymc3/memoize.py
index 55a540ca8d..8b5cfccf1b 100644
--- a/pymc3/memoize.py
+++ b/pymc3/memoize.py
@@ -12,9 +12,11 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import collections
 import functools
+
 import dill
-import collections
+
 from .util import biwrap
 
 CACHE_REGISTRY = []
diff --git a/pymc3/model.py b/pymc3/model.py
index 8b52cdfa5a..9e9c2b4084 100644
--- a/pymc3/model.py
+++ b/pymc3/model.py
@@ -16,27 +16,31 @@
 import itertools
 import threading
 import warnings
-from typing import Optional, TypeVar, Type, List, Union, TYPE_CHECKING, Any, cast
+
 from sys import modules
+from typing import TYPE_CHECKING, Any, List, Optional, Type, TypeVar, Union, cast
 
 import numpy as np
-from pandas import Series
 import scipy.sparse as sps
-import theano.sparse as sparse
 import theano
+import theano.sparse as sparse
 import theano.tensor as tt
-from theano.tensor.var import TensorVariable
+
+from pandas import Series
 from theano.compile import SharedVariable
+from theano.tensor.var import TensorVariable
 
-from pymc3.theanof import set_theano_conf, floatX
 import pymc3 as pm
+
 from pymc3.math import flatten_list
-from .memoize import memoize, WithMemoization
-from .theanof import gradient, hessian, inputvars, generator
-from .vartypes import typefilter, discrete_types, continuous_types, isgenerator
-from .blocking import DictToArrayBijection, ArrayOrdering
-from .util import get_transformed_name, get_var_name
+from pymc3.theanof import floatX, set_theano_conf
+
+from .blocking import ArrayOrdering, DictToArrayBijection
 from .exceptions import ImputationWarning
+from .memoize import WithMemoization, memoize
+from .theanof import generator, gradient, hessian, inputvars
+from .util import get_transformed_name, get_var_name
+from .vartypes import continuous_types, discrete_types, isgenerator, typefilter
 
 __all__ = [
     "Model",
diff --git a/pymc3/model_graph.py b/pymc3/model_graph.py
index b2169dcb36..800cca4222 100644
--- a/pymc3/model_graph.py
+++ b/pymc3/model_graph.py
@@ -13,18 +13,19 @@
 #   limitations under the License.
 
 from collections import deque
-from typing import Dict, Iterator, Set, Optional
+from typing import Dict, Iterator, Optional, Set
 
 VarName = str
 
-from theano.gof.graph import stack_search
 from theano.compile import SharedVariable
+from theano.gof.graph import stack_search
 from theano.tensor import Tensor
 
-from .util import get_default_varnames, get_var_name
-from .model import ObservedRV
 import pymc3 as pm
 
+from .model import ObservedRV
+from .util import get_default_varnames, get_var_name
+
 
 class ModelGraph:
     def __init__(self, model):
diff --git a/pymc3/ode/ode.py b/pymc3/ode/ode.py
index c6bf2c7eae..fe16a7a8ee 100644
--- a/pymc3/ode/ode.py
+++ b/pymc3/ode/ode.py
@@ -13,13 +13,16 @@
 #   limitations under the License.
 
 import logging
+
 import numpy as np
 import scipy
 import theano
 import theano.tensor as tt
+
 from theano.gof.op import get_test_value
+
+from ..exceptions import DtypeError, ShapeError
 from ..ode import utils
-from ..exceptions import ShapeError, DtypeError
 
 _log = logging.getLogger("pymc3")
 floatX = theano.config.floatX
diff --git a/pymc3/parallel_sampling.py b/pymc3/parallel_sampling.py
index c1f13f9bbd..cb57d3f606 100644
--- a/pymc3/parallel_sampling.py
+++ b/pymc3/parallel_sampling.py
@@ -12,20 +12,23 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import multiprocessing
-import multiprocessing.sharedctypes
 import ctypes
-import time
 import logging
+import multiprocessing
+import multiprocessing.sharedctypes
 import pickle
-from collections import namedtuple
-import traceback
 import platform
-from pymc3.exceptions import SamplingError
+import time
+import traceback
+
+from collections import namedtuple
 
 import numpy as np
+
 from fastprogress.fastprogress import progress_bar
 
+from pymc3.exceptions import SamplingError
+
 from . import theanof
 
 logger = logging.getLogger("pymc3")
diff --git a/pymc3/plots/__init__.py b/pymc3/plots/__init__.py
index 219b9e75cf..2224c952b0 100644
--- a/pymc3/plots/__init__.py
+++ b/pymc3/plots/__init__.py
@@ -103,7 +103,6 @@ def compareplot(*args, **kwargs):
 
 from .posteriorplot import plot_posterior_predictive_glm
 
-
 # Access to arviz plots: base plots provided by arviz
 for plot in az.plots.__all__:
     setattr(sys.modules[__name__], plot, map_args(getattr(az.plots, plot)))
diff --git a/pymc3/sampling.py b/pymc3/sampling.py
index bef3f21d73..85a530cfd2 100644
--- a/pymc3/sampling.py
+++ b/pymc3/sampling.py
@@ -14,60 +14,63 @@
 
 """Functions for MCMC sampling."""
 
-from typing import Dict, List, Optional, cast, Union, Any
-from typing import Iterable as TIterable
-from collections.abc import Iterable
-from collections import defaultdict
-from copy import copy
-import packaging
-import pickle
 import logging
+import pickle
+import sys
 import time
 import warnings
 
+from collections import defaultdict
+from collections.abc import Iterable
+from copy import copy
+from typing import Any, Dict
+from typing import Iterable as TIterable
+from typing import List, Optional, Union, cast
+
 import arviz
-from arviz import InferenceData
 import numpy as np
+import packaging
 import theano.gradient as tg
-from theano.tensor import Tensor
 import xarray
 
+from arviz import InferenceData
+from fastprogress.fastprogress import progress_bar
+from theano.tensor import Tensor
+
+import pymc3 as pm
+
+from pymc3.step_methods.hmc import quadpotential
+
 from .backends.base import BaseTrace, MultiTrace
 from .backends.ndarray import NDArray
 from .distributions.distribution import draw_values
 from .distributions.posterior_predictive import fast_sample_posterior_predictive
-from .model import modelcontext, Point, all_continuous, Model
+from .exceptions import IncorrectArgumentsError, SamplingError
+from .model import Model, Point, all_continuous, modelcontext
+from .parallel_sampling import Draw, _cpu_count
 from .step_methods import (
     NUTS,
-    HamiltonianMC,
-    Metropolis,
-    BinaryMetropolis,
+    PGBART,
     BinaryGibbsMetropolis,
+    BinaryMetropolis,
     CategoricalGibbsMetropolis,
+    CompoundStep,
     DEMetropolis,
+    HamiltonianMC,
+    Metropolis,
     Slice,
-    CompoundStep,
     arraystep,
-    PGBART,
 )
 from .util import (
+    chains_and_samples,
     check_start_vals,
-    update_start_vals,
+    dataset_to_point_list,
+    get_default_varnames,
     get_untransformed_name,
     is_transformed_name,
-    get_default_varnames,
-    dataset_to_point_list,
-    chains_and_samples,
+    update_start_vals,
 )
 from .vartypes import discrete_types
-from .exceptions import IncorrectArgumentsError, SamplingError
-from .parallel_sampling import _cpu_count, Draw
-from pymc3.step_methods.hmc import quadpotential
-import pymc3 as pm
-from fastprogress.fastprogress import progress_bar
-
-
-import sys
 
 sys.setrecursionlimit(10000)
 
diff --git a/pymc3/sampling_jax.py b/pymc3/sampling_jax.py
index f7de7570d1..22e686ff88 100644
--- a/pymc3/sampling_jax.py
+++ b/pymc3/sampling_jax.py
@@ -37,9 +37,10 @@ def sample_tfp_nuts(
     num_tuning_epoch=2,
     num_compute_step_size=500,
 ):
-    from tensorflow_probability.substrates import jax as tfp
     import jax
 
+    from tensorflow_probability.substrates import jax as tfp
+
     model = modelcontext(model)
 
     seed = jax.random.PRNGKey(random_seed)
diff --git a/pymc3/smc/sample_smc.py b/pymc3/smc/sample_smc.py
index cd97d6d8fa..9d84737bff 100644
--- a/pymc3/smc/sample_smc.py
+++ b/pymc3/smc/sample_smc.py
@@ -12,17 +12,19 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import time
 import logging
+import multiprocessing as mp
+import time
 import warnings
+
 from collections.abc import Iterable
-import multiprocessing as mp
+
 import numpy as np
 
-from .smc import SMC
-from ..model import modelcontext
 from ..backends.base import MultiTrace
+from ..model import modelcontext
 from ..parallel_sampling import _cpu_count
+from .smc import SMC
 
 
 def sample_smc(
diff --git a/pymc3/smc/smc.py b/pymc3/smc/smc.py
index d606912295..546d9c0409 100644
--- a/pymc3/smc/smc.py
+++ b/pymc3/smc/smc.py
@@ -15,15 +15,16 @@
 from collections import OrderedDict
 
 import numpy as np
+import theano.tensor as tt
+
 from scipy.special import logsumexp
 from scipy.stats import multivariate_normal
 from theano import function as theano_function
-import theano.tensor as tt
 
-from ..model import modelcontext, Point
-from ..theanof import floatX, inputvars, make_shared_replacements, join_nonshared_inputs
-from ..sampling import sample_prior_predictive
 from ..backends.ndarray import NDArray
+from ..model import Point, modelcontext
+from ..sampling import sample_prior_predictive
+from ..theanof import floatX, inputvars, join_nonshared_inputs, make_shared_replacements
 
 
 class SMC:
diff --git a/pymc3/step_methods/__init__.py b/pymc3/step_methods/__init__.py
index a4afd48a3d..27266c4738 100644
--- a/pymc3/step_methods/__init__.py
+++ b/pymc3/step_methods/__init__.py
@@ -13,26 +13,23 @@
 #   limitations under the License.
 
 from .compound import CompoundStep
-
-from .hmc import HamiltonianMC, NUTS
-
-from .metropolis import Metropolis
-from .metropolis import DEMetropolis, DEMetropolisZ
-from .metropolis import BinaryMetropolis
-from .metropolis import BinaryGibbsMetropolis
-from .metropolis import CategoricalGibbsMetropolis
-from .mlda import MLDA, MetropolisMLDA, DEMetropolisZMLDA, RecursiveDAProposal
-from .metropolis import NormalProposal
-from .metropolis import UniformProposal
-from .metropolis import CauchyProposal
-from .metropolis import LaplaceProposal
-from .metropolis import PoissonProposal
-from .metropolis import MultivariateNormalProposal
-
-from .gibbs import ElemwiseCategorical
-
-from .slicer import Slice
-
 from .elliptical_slice import EllipticalSlice
-
+from .gibbs import ElemwiseCategorical
+from .hmc import NUTS, HamiltonianMC
+from .metropolis import (
+    BinaryGibbsMetropolis,
+    BinaryMetropolis,
+    CategoricalGibbsMetropolis,
+    CauchyProposal,
+    DEMetropolis,
+    DEMetropolisZ,
+    LaplaceProposal,
+    Metropolis,
+    MultivariateNormalProposal,
+    NormalProposal,
+    PoissonProposal,
+    UniformProposal,
+)
+from .mlda import MLDA, DEMetropolisZMLDA, MetropolisMLDA, RecursiveDAProposal
 from .pgbart import PGBART
+from .slicer import Slice
diff --git a/pymc3/step_methods/arraystep.py b/pymc3/step_methods/arraystep.py
index d3fc891270..d810460f23 100644
--- a/pymc3/step_methods/arraystep.py
+++ b/pymc3/step_methods/arraystep.py
@@ -12,14 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from .compound import CompoundStep
+from enum import IntEnum, unique
+
+import numpy as np
+
+from numpy.random import uniform
+
+from ..blocking import ArrayOrdering, DictToArrayBijection
 from ..model import modelcontext
 from ..theanof import inputvars
-from ..blocking import ArrayOrdering, DictToArrayBijection
 from ..util import get_var_name
-import numpy as np
-from numpy.random import uniform
-from enum import IntEnum, unique
+from .compound import CompoundStep
 
 __all__ = ["ArrayStep", "ArrayStepShared", "metrop_select", "Competence"]
 
diff --git a/pymc3/step_methods/compound.py b/pymc3/step_methods/compound.py
index 15809ccda4..9e2975ab8b 100644
--- a/pymc3/step_methods/compound.py
+++ b/pymc3/step_methods/compound.py
@@ -18,6 +18,7 @@
 @author: johnsalvatier
 """
 from collections import namedtuple
+
 import numpy as np
 
 
diff --git a/pymc3/step_methods/elliptical_slice.py b/pymc3/step_methods/elliptical_slice.py
index 65944cdf87..73f786e1eb 100644
--- a/pymc3/step_methods/elliptical_slice.py
+++ b/pymc3/step_methods/elliptical_slice.py
@@ -16,10 +16,10 @@
 import numpy.random as nr
 import theano.tensor as tt
 
-from .arraystep import ArrayStep, Competence
+from ..distributions import draw_values
 from ..model import modelcontext
 from ..theanof import inputvars
-from ..distributions import draw_values
+from .arraystep import ArrayStep, Competence
 
 __all__ = ["EllipticalSlice"]
 
diff --git a/pymc3/step_methods/gibbs.py b/pymc3/step_methods/gibbs.py
index 4f1dc09f50..568be5e348 100644
--- a/pymc3/step_methods/gibbs.py
+++ b/pymc3/step_methods/gibbs.py
@@ -17,15 +17,26 @@
 
 @author: john
 """
-from .arraystep import ArrayStep, Competence
-from ..distributions.discrete import Categorical
-from numpy import array, max, exp, cumsum, nested_iters, empty, searchsorted, ones, arange
-from numpy.random import uniform
 from warnings import warn
 
+from numpy import (
+    arange,
+    array,
+    cumsum,
+    empty,
+    exp,
+    max,
+    nested_iters,
+    ones,
+    searchsorted,
+)
+from numpy.random import uniform
 from theano.gof.graph import inputs
 from theano.tensor import add
+
+from ..distributions.discrete import Categorical
 from ..model import modelcontext
+from .arraystep import ArrayStep, Competence
 
 __all__ = ["ElemwiseCategorical"]
 
diff --git a/pymc3/step_methods/hmc/base_hmc.py b/pymc3/step_methods/hmc/base_hmc.py
index 734f51e055..ec0849df01 100644
--- a/pymc3/step_methods/hmc/base_hmc.py
+++ b/pymc3/step_methods/hmc/base_hmc.py
@@ -12,20 +12,22 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from collections import namedtuple
+import logging
 import time
 
+from collections import namedtuple
+
 import numpy as np
-import logging
-from pymc3.model import modelcontext, Point
-from pymc3.step_methods import arraystep
-from pymc3.step_methods.hmc import integration
-from pymc3.theanof import inputvars, floatX
-from pymc3.tuning import guess_scaling
-from .quadpotential import quad_potential, QuadPotentialDiagAdapt
-from pymc3.step_methods import step_sizes
+
 from pymc3.backends.report import SamplerWarning, WarningType
 from pymc3.exceptions import SamplingError
+from pymc3.model import Point, modelcontext
+from pymc3.step_methods import arraystep, step_sizes
+from pymc3.step_methods.hmc import integration
+from pymc3.theanof import floatX, inputvars
+from pymc3.tuning import guess_scaling
+
+from .quadpotential import QuadPotentialDiagAdapt, quad_potential
 
 logger = logging.getLogger("pymc3")
 
diff --git a/pymc3/step_methods/hmc/hmc.py b/pymc3/step_methods/hmc/hmc.py
index 621e7454ce..129abbe123 100644
--- a/pymc3/step_methods/hmc/hmc.py
+++ b/pymc3/step_methods/hmc/hmc.py
@@ -14,11 +14,11 @@
 
 import numpy as np
 
-from ..arraystep import Competence
-from pymc3.vartypes import discrete_types
+from pymc3.step_methods.hmc.base_hmc import BaseHMC, DivergenceInfo, HMCStepData
 from pymc3.step_methods.hmc.integration import IntegrationError
-from pymc3.step_methods.hmc.base_hmc import BaseHMC, HMCStepData, DivergenceInfo
+from pymc3.vartypes import discrete_types
 
+from ..arraystep import Competence
 
 __all__ = ["HamiltonianMC"]
 
diff --git a/pymc3/step_methods/hmc/integration.py b/pymc3/step_methods/hmc/integration.py
index 9cf37978a4..0043d6953a 100644
--- a/pymc3/step_methods/hmc/integration.py
+++ b/pymc3/step_methods/hmc/integration.py
@@ -15,8 +15,8 @@
 from collections import namedtuple
 
 import numpy as np
-from scipy import linalg
 
+from scipy import linalg
 
 State = namedtuple("State", "q, p, v, q_grad, energy, model_logp")
 
diff --git a/pymc3/step_methods/hmc/nuts.py b/pymc3/step_methods/hmc/nuts.py
index 7ffbf106d4..3dbad28c0e 100644
--- a/pymc3/step_methods/hmc/nuts.py
+++ b/pymc3/step_methods/hmc/nuts.py
@@ -16,14 +16,15 @@
 
 import numpy as np
 
-from ..arraystep import Competence
-from .base_hmc import BaseHMC, HMCStepData, DivergenceInfo
-from .integration import IntegrationError
 from pymc3.backends.report import SamplerWarning, WarningType
 from pymc3.math import logbern, logdiffexp_numpy
 from pymc3.theanof import floatX
 from pymc3.vartypes import continuous_types
+
 from ...distributions import BART
+from ..arraystep import Competence
+from .base_hmc import BaseHMC, DivergenceInfo, HMCStepData
+from .integration import IntegrationError
 
 __all__ = ["NUTS"]
 
diff --git a/pymc3/step_methods/hmc/quadpotential.py b/pymc3/step_methods/hmc/quadpotential.py
index 7f6909ae1f..4c2e6acc7a 100644
--- a/pymc3/step_methods/hmc/quadpotential.py
+++ b/pymc3/step_methods/hmc/quadpotential.py
@@ -13,14 +13,15 @@
 #   limitations under the License.
 
 import warnings
+
 import numpy as np
-from numpy.random import normal
 import scipy.linalg
-from scipy.sparse import issparse
 import theano
 
-from pymc3.theanof import floatX
+from numpy.random import normal
+from scipy.sparse import issparse
 
+from pymc3.theanof import floatX
 
 __all__ = [
     "quad_potential",
diff --git a/pymc3/step_methods/metropolis.py b/pymc3/step_methods/metropolis.py
index e7634bd4b5..88622c7dfe 100644
--- a/pymc3/step_methods/metropolis.py
+++ b/pymc3/step_methods/metropolis.py
@@ -14,19 +14,21 @@
 
 import numpy as np
 import numpy.random as nr
-import theano
 import scipy.linalg
+import theano
+
+import pymc3 as pm
+
+from pymc3.theanof import floatX
 
 from ..distributions import draw_values
 from .arraystep import (
+    ArrayStep,
     ArrayStepShared,
+    Competence,
     PopulationArrayStepShared,
-    ArrayStep,
     metrop_select,
-    Competence,
 )
-import pymc3 as pm
-from pymc3.theanof import floatX
 
 __all__ = [
     "Metropolis",
diff --git a/pymc3/step_methods/mlda.py b/pymc3/step_methods/mlda.py
index aa74286701..2a8242e190 100644
--- a/pymc3/step_methods/mlda.py
+++ b/pymc3/step_methods/mlda.py
@@ -12,20 +12,23 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import logging
+import warnings
+
+from typing import List, Optional, Type, Union
+
 import arviz as az
 import numpy as np
-import warnings
-import logging
-from typing import Union, List, Optional, Type
 import theano
 import theano.tensor as tt
 
-from .arraystep import ArrayStepShared, metrop_select, Competence
-from .compound import CompoundStep
-from .metropolis import Proposal, Metropolis, DEMetropolisZ, delta_logp
-from ..model import Model
 import pymc3 as pm
 
+from ..model import Model
+from .arraystep import ArrayStepShared, Competence, metrop_select
+from .compound import CompoundStep
+from .metropolis import DEMetropolisZ, Metropolis, Proposal, delta_logp
+
 __all__ = [
     "MetropolisMLDA",
     "DEMetropolisZMLDA",
diff --git a/pymc3/step_methods/pgbart.py b/pymc3/step_methods/pgbart.py
index 1d6a503c4c..15b8962b7a 100644
--- a/pymc3/step_methods/pgbart.py
+++ b/pymc3/step_methods/pgbart.py
@@ -15,13 +15,14 @@
 import logging
 
 import numpy as np
+
 from theano import function as theano_function
 
-from .arraystep import ArrayStepShared, Competence
 from ..distributions import BART
 from ..distributions.tree import Tree
 from ..model import modelcontext
-from ..theanof import inputvars, make_shared_replacements, join_nonshared_inputs
+from ..theanof import inputvars, join_nonshared_inputs, make_shared_replacements
+from .arraystep import ArrayStepShared, Competence
 
 _log = logging.getLogger("pymc3")
 
diff --git a/pymc3/step_methods/sgmcmc.py b/pymc3/step_methods/sgmcmc.py
index dff75b6621..daa1101652 100644
--- a/pymc3/step_methods/sgmcmc.py
+++ b/pymc3/step_methods/sgmcmc.py
@@ -12,14 +12,16 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from collections import OrderedDict
 import warnings
 
-from .arraystep import ArrayStepShared
-from ..model import modelcontext, inputvars
-import theano.tensor as tt
-from ..theanof import tt_rng, make_shared_replacements
+from collections import OrderedDict
+
 import theano
+import theano.tensor as tt
+
+from ..model import inputvars, modelcontext
+from ..theanof import make_shared_replacements, tt_rng
+from .arraystep import ArrayStepShared
 
 __all__ = []
 
diff --git a/pymc3/step_methods/slicer.py b/pymc3/step_methods/slicer.py
index f6e86e1fbe..f22026adad 100644
--- a/pymc3/step_methods/slicer.py
+++ b/pymc3/step_methods/slicer.py
@@ -17,10 +17,10 @@
 import numpy as np
 import numpy.random as nr
 
-from .arraystep import ArrayStep, Competence
 from ..model import modelcontext
 from ..theanof import inputvars
 from ..vartypes import continuous_types
+from .arraystep import ArrayStep, Competence
 
 __all__ = ["Slice"]
 
diff --git a/pymc3/step_methods/step_sizes.py b/pymc3/step_methods/step_sizes.py
index 3603e30fa5..dbbbf4c16d 100644
--- a/pymc3/step_methods/step_sizes.py
+++ b/pymc3/step_methods/step_sizes.py
@@ -13,6 +13,7 @@
 #   limitations under the License.
 
 import numpy as np
+
 from scipy import stats
 
 from pymc3.backends.report import SamplerWarning, WarningType
diff --git a/pymc3/tests/backend_fixtures.py b/pymc3/tests/backend_fixtures.py
index 919d53948c..6fd0b1318c 100644
--- a/pymc3/tests/backend_fixtures.py
+++ b/pymc3/tests/backend_fixtures.py
@@ -12,17 +12,18 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import numpy as np
-import numpy.testing as npt
+import collections
 import os
 import shutil
-import collections
 
-from pymc3.tests import models
-from pymc3.backends import base
+import numpy as np
+import numpy.testing as npt
 import pytest
 import theano
 
+from pymc3.backends import base
+from pymc3.tests import models
+
 
 class ModelBackendSetupTestCase:
     """Set up a backend trace.
diff --git a/pymc3/tests/conftest.py b/pymc3/tests/conftest.py
index 89484881dd..2964625691 100644
--- a/pymc3/tests/conftest.py
+++ b/pymc3/tests/conftest.py
@@ -13,9 +13,10 @@
 #   limitations under the License.
 
 import numpy as np
+import pytest
 import theano
+
 import pymc3 as pm
-import pytest
 
 
 @pytest.fixture(scope="function", autouse=True)
diff --git a/pymc3/tests/helpers.py b/pymc3/tests/helpers.py
index 44c98e5e96..845eabd2a5 100644
--- a/pymc3/tests/helpers.py
+++ b/pymc3/tests/helpers.py
@@ -12,13 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from logging.handlers import BufferingHandler
 import contextlib
+
+from logging.handlers import BufferingHandler
+
 import numpy.random as nr
-from theano.sandbox.rng_mrg import MRG_RandomStreams
-from ..theanof import set_tt_rng, tt_rng
 import theano
+
 from theano.gradient import verify_grad as tt_verify_grad
+from theano.sandbox.rng_mrg import MRG_RandomStreams
+
+from ..theanof import set_tt_rng, tt_rng
 
 
 class SeededTest:
diff --git a/pymc3/tests/models.py b/pymc3/tests/models.py
index d9a66cee33..5f60734859 100644
--- a/pymc3/tests/models.py
+++ b/pymc3/tests/models.py
@@ -12,13 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from pymc3 import Model, Normal, Categorical, Metropolis
-import numpy as np
-import pymc3 as pm
 from itertools import product
-import theano.tensor as tt
+
+import numpy as np
 import theano
+import theano.tensor as tt
+
 from theano.compile.ops import as_op
+
+import pymc3 as pm
+
+from pymc3 import Categorical, Metropolis, Model, Normal
 from pymc3.theanof import floatX_array
 
 
diff --git a/pymc3/tests/sampler_fixtures.py b/pymc3/tests/sampler_fixtures.py
index 422b270d1d..2f71e7ffcc 100644
--- a/pymc3/tests/sampler_fixtures.py
+++ b/pymc3/tests/sampler_fixtures.py
@@ -12,13 +12,16 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
-from pymc3.util import get_var_name
 import numpy as np
 import numpy.testing as npt
-from scipy import stats
 import theano.tensor as tt
 
+from scipy import stats
+
+import pymc3 as pm
+
+from pymc3.util import get_var_name
+
 from .helpers import SeededTest
 
 
diff --git a/pymc3/tests/test_coords.py b/pymc3/tests/test_coords.py
index 2f7f24b320..18d4a94e09 100644
--- a/pymc3/tests/test_coords.py
+++ b/pymc3/tests/test_coords.py
@@ -1,6 +1,7 @@
-import pymc3 as pm
 import numpy as np
 
+import pymc3 as pm
+
 
 def test_coords():
     chains = 2
diff --git a/pymc3/tests/test_data_container.py b/pymc3/tests/test_data_container.py
index 5b384ccc99..0fb54499c0 100644
--- a/pymc3/tests/test_data_container.py
+++ b/pymc3/tests/test_data_container.py
@@ -12,13 +12,15 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
-from ..theanof import floatX
-from .helpers import SeededTest
 import numpy as np
 import pandas as pd
 import pytest
 
+import pymc3 as pm
+
+from ..theanof import floatX
+from .helpers import SeededTest
+
 
 class TestData(SeededTest):
     def test_deterministic(self):
diff --git a/pymc3/tests/test_dist_math.py b/pymc3/tests/test_dist_math.py
index 599bb2bc88..454b1ae4bf 100644
--- a/pymc3/tests/test_dist_math.py
+++ b/pymc3/tests/test_dist_math.py
@@ -14,23 +14,25 @@
 
 import numpy as np
 import numpy.testing as npt
-import theano.tensor as tt
+import pytest
 import theano
+import theano.tensor as tt
+
+from scipy import interpolate, stats
+
 import pymc3 as pm
-from scipy import stats, interpolate
-import pytest
 
-from ..theanof import floatX
 from ..distributions import Discrete
 from ..distributions.dist_math import (
-    bound,
-    factln,
-    alltrue_scalar,
     MvNormalLogp,
     SplineWrapper,
-    i0e,
+    alltrue_scalar,
+    bound,
     clipped_beta_rvs,
+    factln,
+    i0e,
 )
+from ..theanof import floatX
 from .helpers import verify_grad
 
 
diff --git a/pymc3/tests/test_distribution_defaults.py b/pymc3/tests/test_distribution_defaults.py
index 5ae8b3bf82..1192aa618c 100644
--- a/pymc3/tests/test_distribution_defaults.py
+++ b/pymc3/tests/test_distribution_defaults.py
@@ -12,12 +12,12 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from ..model import Model
-from ..distributions import DiscreteUniform, Continuous, Categorical
-
 import numpy as np
 import pytest
 
+from ..distributions import Categorical, Continuous, DiscreteUniform
+from ..model import Model
+
 
 class DistTest(Continuous):
     def __init__(self, a, b, *args, **kwargs):
diff --git a/pymc3/tests/test_distributions.py b/pymc3/tests/test_distributions.py
index f7210264f1..a69079f6da 100644
--- a/pymc3/tests/test_distributions.py
+++ b/pymc3/tests/test_distributions.py
@@ -15,85 +15,87 @@
 import itertools
 import sys
 
-from .helpers import SeededTest, select_by_precision
-from ..vartypes import continuous_types
-from ..model import Model, Point, Deterministic
+import numpy as np
+import numpy.random as nr
+import pytest
+import scipy.stats
+import scipy.stats.distributions as sp
+import theano
+import theano.tensor as tt
+
+from numpy import array, exp, inf, log
+from numpy.testing import assert_allclose, assert_almost_equal, assert_equal
+from scipy import integrate
+from scipy.special import logit
+
+import pymc3 as pm
+
+from pymc3.theanof import floatX
+
 from ..blocking import DictToVarBijection
 from ..distributions import (
-    DensityDist,
-    Categorical,
-    Multinomial,
-    VonMises,
-    Dirichlet,
-    MvStudentT,
-    MvNormal,
-    MatrixNormal,
-    ZeroInflatedPoisson,
-    ZeroInflatedNegativeBinomial,
-    Constant,
-    Poisson,
+    AR1,
     Bernoulli,
     Beta,
     BetaBinomial,
-    HalfStudentT,
-    StudentT,
-    Weibull,
-    Pareto,
-    InverseGamma,
-    Gamma,
+    Binomial,
+    Bound,
+    Categorical,
     Cauchy,
-    HalfCauchy,
-    Lognormal,
-    Laplace,
-    NegativeBinomial,
-    Geometric,
-    Exponential,
-    ExGaussian,
-    Normal,
-    TruncatedNormal,
-    Flat,
-    LKJCorr,
-    Wald,
     ChiSquared,
-    HalfNormal,
+    Constant,
+    DensityDist,
+    Dirichlet,
     DiscreteUniform,
-    Bound,
-    Uniform,
-    Triangular,
-    Binomial,
-    SkewNormal,
     DiscreteWeibull,
+    ExGaussian,
+    Exponential,
+    Flat,
+    Gamma,
+    Geometric,
     Gumbel,
-    Logistic,
-    OrderedLogistic,
-    LogitNormal,
-    Interpolated,
-    ZeroInflatedBinomial,
+    HalfCauchy,
     HalfFlat,
-    AR1,
+    HalfNormal,
+    HalfStudentT,
+    HyperGeometric,
+    Interpolated,
+    InverseGamma,
     KroneckerNormal,
-    Rice,
     Kumaraswamy,
+    Laplace,
+    LKJCorr,
+    Logistic,
+    LogitNormal,
+    Lognormal,
+    MatrixNormal,
     Moyal,
-    HyperGeometric,
+    Multinomial,
+    MvNormal,
+    MvStudentT,
+    NegativeBinomial,
+    Normal,
+    OrderedLogistic,
+    Pareto,
+    Poisson,
+    Rice,
+    SkewNormal,
+    StudentT,
+    Triangular,
+    TruncatedNormal,
+    Uniform,
+    VonMises,
+    Wald,
+    Weibull,
+    ZeroInflatedBinomial,
+    ZeroInflatedNegativeBinomial,
+    ZeroInflatedPoisson,
+    continuous,
 )
-
-from ..distributions import continuous
-from pymc3.theanof import floatX
-import pymc3 as pm
-from numpy import array, inf, log, exp
-from numpy.testing import assert_almost_equal, assert_allclose, assert_equal
-import numpy.random as nr
-import numpy as np
-import pytest
-
-from scipy import integrate
-import scipy.stats.distributions as sp
-import scipy.stats
-from scipy.special import logit
-import theano
-import theano.tensor as tt
 from ..math import kronecker
+from ..model import Deterministic, Model, Point
+from ..vartypes import continuous_types
+from .helpers import SeededTest, select_by_precision
 
 
 def get_lkj_cases():
diff --git a/pymc3/tests/test_distributions_random.py b/pymc3/tests/test_distributions_random.py
index 2b9358787c..d37375c45e 100644
--- a/pymc3/tests/test_distributions_random.py
+++ b/pymc3/tests/test_distributions_random.py
@@ -13,45 +13,49 @@
 #   limitations under the License.
 
 import itertools
-import pytest
+import sys
+
 import numpy as np
+import numpy.random as nr
 import numpy.testing as npt
+import pytest
 import scipy.stats as st
-from scipy.special import expit
-from scipy import linalg
-import numpy.random as nr
 import theano
-import sys
+
+from scipy import linalg
+from scipy.special import expit
 
 import pymc3 as pm
+
 from pymc3.distributions.dist_math import clipped_beta_rvs
 from pymc3.distributions.distribution import (
-    draw_values,
     _DrawValuesContext,
     _DrawValuesContextBlocker,
+    draw_values,
     to_tuple,
 )
+
 from .helpers import SeededTest
 from .test_distributions import (
-    build_model,
     Domain,
-    product,
-    R,
-    Rplus,
-    Rplusbig,
-    Runif,
-    Rplusdunif,
-    Unit,
+    I,
     Nat,
     NatSmall,
-    I,
-    Simplex,
-    Vector,
     PdMatrix,
     PdMatrixChol,
     PdMatrixCholUpper,
-    RealMatrix,
+    R,
     RandomPdMatrix,
+    RealMatrix,
+    Rplus,
+    Rplusbig,
+    Rplusdunif,
+    Runif,
+    Simplex,
+    Unit,
+    Vector,
+    build_model,
+    product,
 )
 
 
diff --git a/pymc3/tests/test_distributions_timeseries.py b/pymc3/tests/test_distributions_timeseries.py
index c55f71a388..9c47e511f0 100644
--- a/pymc3/tests/test_distributions_timeseries.py
+++ b/pymc3/tests/test_distributions_timeseries.py
@@ -12,14 +12,18 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from ..model import Model
-from ..distributions.continuous import Flat, Normal
-from ..distributions.timeseries import EulerMaruyama, AR1, AR, GARCH11
-from ..sampling import sample, sample_posterior_predictive, fast_sample_posterior_predictive
-from ..theanof import floatX
-
 import numpy as np
 import pytest
+
+from ..distributions.continuous import Flat, Normal
+from ..distributions.timeseries import AR, AR1, GARCH11, EulerMaruyama
+from ..model import Model
+from ..sampling import (
+    fast_sample_posterior_predictive,
+    sample,
+    sample_posterior_predictive,
+)
+from ..theanof import floatX
 from .helpers import select_by_precision
 
 pytestmark = pytest.mark.usefixtures("seeded_test")
diff --git a/pymc3/tests/test_examples.py b/pymc3/tests/test_examples.py
index d31b2bfd3a..c24abfdf2b 100644
--- a/pymc3/tests/test_examples.py
+++ b/pymc3/tests/test_examples.py
@@ -15,13 +15,16 @@
 import matplotlib
 import numpy as np
 import pandas as pd
-import pymc3 as pm
-import theano.tensor as tt
 import pytest
 import theano
-from pymc3.theanof import floatX
+import theano.tensor as tt
+
 from packaging import version
 
+import pymc3 as pm
+
+from pymc3.theanof import floatX
+
 from .helpers import SeededTest
 
 if version.parse(matplotlib.__version__) < version.parse("3.3"):
diff --git a/pymc3/tests/test_glm.py b/pymc3/tests/test_glm.py
index 3d66211b8d..eea40aed33 100644
--- a/pymc3/tests/test_glm.py
+++ b/pymc3/tests/test_glm.py
@@ -13,13 +13,26 @@
 #   limitations under the License.
 
 import numpy as np
+import pandas as pd
+
 from numpy.testing import assert_equal
 
-from .helpers import SeededTest
 import pymc3
-from pymc3 import Model, Uniform, Normal, find_MAP, Slice, sample
-from pymc3 import families, GLM, LinearComponent
-import pandas as pd
+
+from pymc3 import (
+    GLM,
+    LinearComponent,
+    Model,
+    Normal,
+    Slice,
+    Uniform,
+    families,
+    find_MAP,
+    sample,
+)
+
+from .helpers import SeededTest
+
 
 # Generate data
 def generate_data(intercept, slope, size=700):
diff --git a/pymc3/tests/test_gp.py b/pymc3/tests/test_gp.py
index 7aed383422..a57b84b234 100644
--- a/pymc3/tests/test_gp.py
+++ b/pymc3/tests/test_gp.py
@@ -14,14 +14,17 @@
 
 #  pylint:disable=unused-variable
 from functools import reduce
-from ..math import cartesian, kronecker
 from operator import add
-import pymc3 as pm
-import theano
-import theano.tensor as tt
+
 import numpy as np
 import numpy.testing as npt
 import pytest
+import theano
+import theano.tensor as tt
+
+import pymc3 as pm
+
+from ..math import cartesian, kronecker
 
 np.random.seed(101)
 
diff --git a/pymc3/tests/test_hmc.py b/pymc3/tests/test_hmc.py
index 384501f2fd..f06cce6237 100644
--- a/pymc3/tests/test_hmc.py
+++ b/pymc3/tests/test_hmc.py
@@ -12,15 +12,18 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import logging
+
 import numpy as np
 import numpy.testing as npt
 
-from . import models
-from pymc3.step_methods.hmc.base_hmc import BaseHMC
 import pymc3
-import logging
+
+from pymc3.step_methods.hmc.base_hmc import BaseHMC
 from pymc3.theanof import floatX
 
+from . import models
+
 logger = logging.getLogger("pymc3")
 
 
diff --git a/pymc3/tests/test_math.py b/pymc3/tests/test_math.py
index 7783b65261..e0bfeb6eff 100644
--- a/pymc3/tests/test_math.py
+++ b/pymc3/tests/test_math.py
@@ -14,26 +14,28 @@
 
 import numpy as np
 import numpy.testing as npt
+import pytest
 import theano
 import theano.tensor as tt
+
 from pymc3.math import (
     LogDet,
-    logdet,
-    probit,
-    invprobit,
-    expand_packed_triangular,
-    log1pexp,
-    log1mexp,
-    log1mexp_numpy,
-    kronecker,
     cartesian,
+    expand_packed_triangular,
+    invprobit,
     kron_dot,
     kron_solve_lower,
+    kronecker,
+    log1mexp,
+    log1mexp_numpy,
+    log1pexp,
+    logdet,
+    probit,
 )
-from .helpers import SeededTest, verify_grad
-import pytest
 from pymc3.theanof import floatX
 
+from .helpers import SeededTest, verify_grad
+
 
 def test_kronecker():
     np.random.seed(1)
diff --git a/pymc3/tests/test_memo.py b/pymc3/tests/test_memo.py
index 4d1955a442..6653662e32 100644
--- a/pymc3/tests/test_memo.py
+++ b/pymc3/tests/test_memo.py
@@ -12,6 +12,7 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 import numpy as np
+
 import pymc3 as pm
 
 from pymc3 import memoize
diff --git a/pymc3/tests/test_minibatches.py b/pymc3/tests/test_minibatches.py
index e2254da847..34dadaa8eb 100644
--- a/pymc3/tests/test_minibatches.py
+++ b/pymc3/tests/test_minibatches.py
@@ -17,12 +17,14 @@
 
 import numpy as np
 import pytest
+import theano
+
 from scipy import stats as stats
 from theano import tensor as tt
-import theano
 
 import pymc3 as pm
-from pymc3 import floatX, GeneratorAdapter, generator, tt_rng, Normal
+
+from pymc3 import GeneratorAdapter, Normal, floatX, generator, tt_rng
 from pymc3.tests.helpers import select_by_precision
 from pymc3.theanof import GeneratorOp
 
diff --git a/pymc3/tests/test_missing.py b/pymc3/tests/test_missing.py
index adb54822d2..65248f6b2d 100644
--- a/pymc3/tests/test_missing.py
+++ b/pymc3/tests/test_missing.py
@@ -12,11 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pytest
-from numpy import ma, array
 import numpy
 import pandas as pd
-from pymc3 import Model, Normal, sample_prior_predictive, sample, ImputationWarning
+import pytest
+
+from numpy import array, ma
+
+from pymc3 import ImputationWarning, Model, Normal, sample, sample_prior_predictive
 
 
 def test_missing():
diff --git a/pymc3/tests/test_mixture.py b/pymc3/tests/test_mixture.py
index 9f016ad333..b36d0dbe25 100644
--- a/pymc3/tests/test_mixture.py
+++ b/pymc3/tests/test_mixture.py
@@ -12,32 +12,36 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pytest
 import numpy as np
+import pytest
+import scipy.stats as st
+import theano
+
 from numpy.testing import assert_allclose
+from scipy.special import logsumexp
+from theano import tensor as tt
 
-from .helpers import SeededTest
 import pymc3 as pm
+
 from pymc3 import (
     Dirichlet,
+    Exponential,
     Gamma,
-    Normal,
     Lognormal,
-    Poisson,
-    Exponential,
+    Metropolis,
     Mixture,
-    NormalMixture,
+    Model,
     MvNormal,
+    Normal,
+    NormalMixture,
+    Poisson,
     sample,
-    Metropolis,
-    Model,
 )
-import scipy.stats as st
-from scipy.special import logsumexp
-from pymc3.theanof import floatX
-import theano
-from theano import tensor as tt
 from pymc3.distributions.shape_utils import to_tuple
+from pymc3.theanof import floatX
+
+from .helpers import SeededTest
+
 
 # Generate data
 def generate_normal_mixture_data(w, mu, sd, size=1000):
diff --git a/pymc3/tests/test_model.py b/pymc3/tests/test_model.py
index 1cea9840fd..5a57306721 100644
--- a/pymc3/tests/test_model.py
+++ b/pymc3/tests/test_model.py
@@ -12,19 +12,22 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import pickle
+import unittest
+
+import numpy as np
+import numpy.testing as npt
+import pandas as pd
 import pytest
 import theano
 import theano.tensor as tt
-import numpy as np
-import pickle
-import pandas as pd
-import numpy.testing as npt
-import unittest
 
 import pymc3 as pm
+
+from pymc3 import Deterministic, Potential
 from pymc3.distributions import HalfCauchy, Normal, transforms
-from pymc3 import Potential, Deterministic
 from pymc3.model import ValueGradFunction
+
 from .helpers import select_by_precision
 
 
diff --git a/pymc3/tests/test_model_func.py b/pymc3/tests/test_model_func.py
index 5c167c099a..3879fc2199 100644
--- a/pymc3/tests/test_model_func.py
+++ b/pymc3/tests/test_model_func.py
@@ -12,12 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
 import numpy as np
 import scipy.stats as sp
-from .checks import close_to
-from .models import simple_model, mv_simple
 
+import pymc3 as pm
+
+from .checks import close_to
+from .models import mv_simple, simple_model
 
 tol = 2.0 ** -11
 
diff --git a/pymc3/tests/test_model_graph.py b/pymc3/tests/test_model_graph.py
index 4ecf10c8b5..09b673e973 100644
--- a/pymc3/tests/test_model_graph.py
+++ b/pymc3/tests/test_model_graph.py
@@ -13,9 +13,12 @@
 #   limitations under the License.
 
 import numpy as np
-import pymc3 as pm
 import theano as th
+
+import pymc3 as pm
+
 from pymc3.model_graph import ModelGraph, model_to_graphviz
+
 from .helpers import SeededTest
 
 
diff --git a/pymc3/tests/test_model_helpers.py b/pymc3/tests/test_model_helpers.py
index 676cd75e7a..62312c4428 100644
--- a/pymc3/tests/test_model_helpers.py
+++ b/pymc3/tests/test_model_helpers.py
@@ -16,12 +16,12 @@
 import numpy.ma as ma
 import numpy.testing as npt
 import pandas as pd
-import pymc3 as pm
 import scipy.sparse as sps
-
 import theano
-import theano.tensor as tt
 import theano.sparse as sparse
+import theano.tensor as tt
+
+import pymc3 as pm
 
 
 class TestHelperFunc:
diff --git a/pymc3/tests/test_modelcontext.py b/pymc3/tests/test_modelcontext.py
index d7cc4a6166..b7d44ca63c 100644
--- a/pymc3/tests/test_modelcontext.py
+++ b/pymc3/tests/test_modelcontext.py
@@ -13,9 +13,14 @@
 #   limitations under the License.
 
 import threading
+
 from pytest import raises
+
 from pymc3 import Model, Normal
-from pymc3.distributions.distribution import _DrawValuesContext, _DrawValuesContextBlocker
+from pymc3.distributions.distribution import (
+    _DrawValuesContext,
+    _DrawValuesContextBlocker,
+)
 from pymc3.model import modelcontext
 
 
diff --git a/pymc3/tests/test_models_linear.py b/pymc3/tests/test_models_linear.py
index b95795a35a..fdd1b920b9 100644
--- a/pymc3/tests/test_models_linear.py
+++ b/pymc3/tests/test_models_linear.py
@@ -13,11 +13,13 @@
 #   limitations under the License.
 
 import numpy as np
-from .helpers import SeededTest
-from pymc3 import Model, Uniform, Normal, find_MAP, Slice, sample
-from pymc3.glm import LinearComponent, GLM
 import pytest
 
+from pymc3 import Model, Normal, Slice, Uniform, find_MAP, sample
+from pymc3.glm import GLM, LinearComponent
+
+from .helpers import SeededTest
+
 
 # Generate data
 def generate_data(intercept, slope, size=700):
diff --git a/pymc3/tests/test_models_utils.py b/pymc3/tests/test_models_utils.py
index 4b1e5f42bc..84d25b3c2b 100644
--- a/pymc3/tests/test_models_utils.py
+++ b/pymc3/tests/test_models_utils.py
@@ -14,9 +14,10 @@
 
 import numpy as np
 import pandas as pd
+import pytest
 import theano.tensor as tt
+
 from pymc3.glm import utils
-import pytest
 
 
 class TestUtils:
diff --git a/pymc3/tests/test_ndarray_backend.py b/pymc3/tests/test_ndarray_backend.py
index 7a0a0bfc5d..1b13aa0b0f 100644
--- a/pymc3/tests/test_ndarray_backend.py
+++ b/pymc3/tests/test_ndarray_backend.py
@@ -14,11 +14,12 @@
 
 import numpy as np
 import numpy.testing as npt
-from pymc3.tests import backend_fixtures as bf
-from pymc3.backends import base, ndarray
-import pymc3 as pm
 import pytest
 
+import pymc3 as pm
+
+from pymc3.backends import base, ndarray
+from pymc3.tests import backend_fixtures as bf
 
 STATS1 = [{"a": np.float64, "b": np.bool}]
 
diff --git a/pymc3/tests/test_ode.py b/pymc3/tests/test_ode.py
index 0fbc21232d..b498ce1d33 100644
--- a/pymc3/tests/test_ode.py
+++ b/pymc3/tests/test_ode.py
@@ -12,14 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from ..ode import DifferentialEquation
-from ..ode.utils import augment_system
 import numpy as np
+import pytest
+import theano
+
 from scipy.integrate import odeint
 from scipy.stats import norm
+
 import pymc3 as pm
-import theano
-import pytest
+
+from ..ode import DifferentialEquation
+from ..ode.utils import augment_system
 
 
 def test_gradients():
diff --git a/pymc3/tests/test_parallel_sampling.py b/pymc3/tests/test_parallel_sampling.py
index 21715d6591..4d5403a940 100644
--- a/pymc3/tests/test_parallel_sampling.py
+++ b/pymc3/tests/test_parallel_sampling.py
@@ -14,12 +14,13 @@
 import multiprocessing
 import os
 
+import numpy as np
 import pytest
-import pymc3.parallel_sampling as ps
-import pymc3 as pm
 import theano
 import theano.tensor as tt
-import numpy as np
+
+import pymc3 as pm
+import pymc3.parallel_sampling as ps
 
 
 def test_context():
diff --git a/pymc3/tests/test_pickling.py b/pymc3/tests/test_pickling.py
index 7cb56c4a31..20eaa1d5d0 100644
--- a/pymc3/tests/test_pickling.py
+++ b/pymc3/tests/test_pickling.py
@@ -14,6 +14,7 @@
 
 import pickle
 import traceback
+
 from .models import simple_model
 
 
diff --git a/pymc3/tests/test_posdef_sym.py b/pymc3/tests/test_posdef_sym.py
index a71c500649..a7aa714357 100644
--- a/pymc3/tests/test_posdef_sym.py
+++ b/pymc3/tests/test_posdef_sym.py
@@ -12,9 +12,10 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from pymc3.distributions import multivariate as mv
-import theano
 import numpy as np
+import theano
+
+from pymc3.distributions import multivariate as mv
 
 
 def test_posdef_symmetric1():
diff --git a/pymc3/tests/test_posterior_predictive.py b/pymc3/tests/test_posterior_predictive.py
index 7e812c7955..7a19ac4a59 100644
--- a/pymc3/tests/test_posterior_predictive.py
+++ b/pymc3/tests/test_posterior_predictive.py
@@ -1,8 +1,9 @@
-import pymc3 as pm
-from pymc3.distributions.posterior_predictive import _TraceDict
 import numpy as np
 
+import pymc3 as pm
+
 from pymc3.backends.ndarray import point_list_to_multitrace
+from pymc3.distributions.posterior_predictive import _TraceDict
 
 
 def test_translate_point_list():
diff --git a/pymc3/tests/test_posteriors.py b/pymc3/tests/test_posteriors.py
index c4281a32ab..e484a9a4b0 100644
--- a/pymc3/tests/test_posteriors.py
+++ b/pymc3/tests/test_posteriors.py
@@ -13,9 +13,10 @@
 #   limitations under the License.
 
 import pytest
-from . import sampler_fixtures as sf
 import theano
 
+from . import sampler_fixtures as sf
+
 
 @pytest.mark.xfail(condition=(theano.config.floatX == "float32"), reason="Fails on float32")
 class TestNUTSUniform(sf.NutsFixture, sf.UniformFixture):
diff --git a/pymc3/tests/test_quadpotential.py b/pymc3/tests/test_quadpotential.py
index c964f05f83..d91a80b5e9 100644
--- a/pymc3/tests/test_quadpotential.py
+++ b/pymc3/tests/test_quadpotential.py
@@ -13,13 +13,14 @@
 #   limitations under the License.
 
 import numpy as np
+import numpy.testing as npt
+import pytest
 import scipy.sparse
 
-from pymc3.step_methods.hmc import quadpotential
 import pymc3
+
+from pymc3.step_methods.hmc import quadpotential
 from pymc3.theanof import floatX
-import pytest
-import numpy.testing as npt
 
 
 def test_elemwise_posdef():
diff --git a/pymc3/tests/test_random.py b/pymc3/tests/test_random.py
index 5e47961a5e..b21d58c081 100644
--- a/pymc3/tests/test_random.py
+++ b/pymc3/tests/test_random.py
@@ -12,15 +12,18 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
 import numpy as np
-from numpy import random as nr
 import numpy.testing as npt
 import pytest
-import theano.tensor as tt
 import theano
+import theano.tensor as tt
+
+from numpy import random as nr
+
+import pymc3 as pm
 
 from pymc3.distributions.distribution import _draw_value, draw_values
+
 from .helpers import SeededTest
 
 
diff --git a/pymc3/tests/test_sampling.py b/pymc3/tests/test_sampling.py
index 2fd2d916c3..a167b4f759 100644
--- a/pymc3/tests/test_sampling.py
+++ b/pymc3/tests/test_sampling.py
@@ -12,23 +12,27 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import unittest.mock as mock
+
 from contextlib import ExitStack as does_not_raise
 from itertools import combinations
 from typing import Tuple
-import numpy as np
-import unittest.mock as mock
 
-import numpy.testing as npt
 import arviz as az
-import pymc3 as pm
+import numpy as np
+import numpy.testing as npt
+import pytest
+import theano
 import theano.tensor as tt
+
+from scipy import stats
 from theano import shared
-import theano
-from pymc3.tests.models import simple_init
-from pymc3.tests.helpers import SeededTest
+
+import pymc3 as pm
+
 from pymc3.exceptions import IncorrectArgumentsError, SamplingError
-from scipy import stats
-import pytest
+from pymc3.tests.helpers import SeededTest
+from pymc3.tests.models import simple_init
 
 
 @pytest.mark.xfail(condition=(theano.config.floatX == "float32"), reason="Fails on float32")
diff --git a/pymc3/tests/test_shape_handling.py b/pymc3/tests/test_shape_handling.py
index 50ed4a24fd..f5d830617a 100644
--- a/pymc3/tests/test_shape_handling.py
+++ b/pymc3/tests/test_shape_handling.py
@@ -12,17 +12,20 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pytest
 import numpy as np
+import pytest
+
 from theano import tensor as tt
+
 import pymc3 as pm
+
 from pymc3.distributions.shape_utils import (
-    to_tuple,
-    shapes_broadcasting,
     broadcast_dist_samples_shape,
-    get_broadcastable_dist_samples,
-    broadcast_distribution_samples,
     broadcast_dist_samples_to,
+    broadcast_distribution_samples,
+    get_broadcastable_dist_samples,
+    shapes_broadcasting,
+    to_tuple,
 )
 
 test_shapes = [
diff --git a/pymc3/tests/test_shared.py b/pymc3/tests/test_shared.py
index ded4861934..6be4d26577 100644
--- a/pymc3/tests/test_shared.py
+++ b/pymc3/tests/test_shared.py
@@ -12,11 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
-from .helpers import SeededTest
 import numpy as np
 import theano
 
+import pymc3 as pm
+
+from .helpers import SeededTest
+
 
 class TestShared(SeededTest):
     def test_deterministic(self):
diff --git a/pymc3/tests/test_smc.py b/pymc3/tests/test_smc.py
index 532a2844ac..c17db977a2 100644
--- a/pymc3/tests/test_smc.py
+++ b/pymc3/tests/test_smc.py
@@ -12,9 +12,11 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3 as pm
 import numpy as np
 import theano.tensor as tt
+
+import pymc3 as pm
+
 from .helpers import SeededTest
 
 
diff --git a/pymc3/tests/test_special_functions.py b/pymc3/tests/test_special_functions.py
index 9997135479..b7e5fe2582 100644
--- a/pymc3/tests/test_special_functions.py
+++ b/pymc3/tests/test_special_functions.py
@@ -12,12 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from theano import function
+import numpy as np
+import scipy.special as ss
 import theano.tensor as tt
 
+from theano import function
+
 import pymc3.distributions.special as ps
-import scipy.special as ss
-import numpy as np
 
 from .checks import close_to
 
diff --git a/pymc3/tests/test_starting.py b/pymc3/tests/test_starting.py
index 5cc1ae3d77..740cd696cc 100644
--- a/pymc3/tests/test_starting.py
+++ b/pymc3/tests/test_starting.py
@@ -12,15 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from .checks import close_to
 import numpy as np
-from pymc3.tuning import starting
-from pymc3 import Model, Uniform, Normal, Beta, Binomial, find_MAP, Point
-from .models import simple_model, non_normal, simple_arbitrary_det
-from .helpers import select_by_precision
 
 from pytest import raises
 
+from pymc3 import Beta, Binomial, Model, Normal, Point, Uniform, find_MAP
+from pymc3.tuning import starting
+
+from .checks import close_to
+from .helpers import select_by_precision
+from .models import non_normal, simple_arbitrary_det, simple_model
+
 
 def test_accuracy_normal():
     _, model, (mu, _) = simple_model()
diff --git a/pymc3/tests/test_step.py b/pymc3/tests/test_step.py
index e115bdcb17..eb1fe5e256 100644
--- a/pymc3/tests/test_step.py
+++ b/pymc3/tests/test_step.py
@@ -13,54 +13,64 @@
 #   limitations under the License.
 
 import shutil
-import tempfile
 import sys
+import tempfile
 
-from .checks import close_to
-from .models import (
-    simple_categorical,
-    mv_simple,
-    mv_simple_coarse,
-    mv_simple_very_coarse,
-    mv_simple_discrete,
-    mv_prior_simple,
-    simple_2model_continuous,
+from math import isclose
+
+import arviz as az
+import numpy as np
+import numpy.testing as npt
+import pytest
+import theano
+import theano.tensor as tt
+
+from numpy.testing import assert_array_almost_equal
+
+from pymc3.data import Data
+from pymc3.distributions import (
+    Bernoulli,
+    Beta,
+    Binomial,
+    Categorical,
+    HalfNormal,
+    MvNormal,
+    Normal,
 )
-from pymc3.sampling import assign_step_methods, sample
 from pymc3.exceptions import SamplingError
 from pymc3.model import Model, Potential, set_data
-
+from pymc3.sampling import assign_step_methods, sample
 from pymc3.step_methods import (
+    MLDA,
     NUTS,
     BinaryGibbsMetropolis,
     CategoricalGibbsMetropolis,
-    Metropolis,
-    Slice,
     CompoundStep,
-    NormalProposal,
-    UniformProposal,
-    MultivariateNormalProposal,
-    RecursiveDAProposal,
-    HamiltonianMC,
-    EllipticalSlice,
     DEMetropolis,
     DEMetropolisZ,
-    MLDA,
+    EllipticalSlice,
+    HamiltonianMC,
+    Metropolis,
+    MultivariateNormalProposal,
+    NormalProposal,
+    RecursiveDAProposal,
+    Slice,
+    UniformProposal,
 )
 from pymc3.step_methods.mlda import extract_Q_estimate
 from pymc3.theanof import floatX
-from pymc3.distributions import Binomial, Normal, Bernoulli, Categorical, Beta, HalfNormal, MvNormal
-from pymc3.data import Data
 
-from numpy.testing import assert_array_almost_equal
-import arviz as az
-import numpy as np
-import numpy.testing as npt
-import pytest
-import theano
-import theano.tensor as tt
+from .checks import close_to
 from .helpers import select_by_precision
-from math import isclose
+from .models import (
+    mv_prior_simple,
+    mv_simple,
+    mv_simple_coarse,
+    mv_simple_discrete,
+    mv_simple_very_coarse,
+    simple_2model_continuous,
+    simple_categorical,
+)
 
 
 class TestStepMethods:  # yield test doesn't work subclassing object
diff --git a/pymc3/tests/test_theanof.py b/pymc3/tests/test_theanof.py
index 82dbf51750..8d51554adb 100644
--- a/pymc3/tests/test_theanof.py
+++ b/pymc3/tests/test_theanof.py
@@ -13,17 +13,17 @@
 #   limitations under the License.
 
 import collections
-import pytest
+
 from itertools import product
 
+import numpy as np
+import pytest
 import theano
 import theano.tensor as tt
-import numpy as np
 
-from pymc3.theanof import set_theano_conf, take_along_axis, _conversion_map
+from pymc3.theanof import _conversion_map, set_theano_conf, take_along_axis
 from pymc3.vartypes import int_types
 
-
 FLOATX = str(theano.config.floatX)
 INTX = str(_conversion_map[FLOATX])
 
diff --git a/pymc3/tests/test_tracetab.py b/pymc3/tests/test_tracetab.py
index cdfdafd5ab..cff6b33b3c 100644
--- a/pymc3/tests/test_tracetab.py
+++ b/pymc3/tests/test_tracetab.py
@@ -14,9 +14,9 @@
 
 import numpy.testing as npt
 
-from pymc3.tests import backend_fixtures as bf
 from pymc3.backends import ndarray
 from pymc3.backends import tracetab as ttab
+from pymc3.tests import backend_fixtures as bf
 
 
 class TestTraceToDf(bf.ModelBackendSampledTestCase):
diff --git a/pymc3/tests/test_transforms.py b/pymc3/tests/test_transforms.py
index c375a30449..5e4840d0f5 100644
--- a/pymc3/tests/test_transforms.py
+++ b/pymc3/tests/test_transforms.py
@@ -12,29 +12,29 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pymc3.distributions.transforms as tr
-import pymc3 as pm
 import numpy as np
 import pytest
-
 import theano
 import theano.tensor as tt
+
+import pymc3 as pm
+import pymc3.distributions.transforms as tr
+
+from ..theanof import jacobian
+from .checks import close_to, close_to_logical
 from .helpers import SeededTest
 from .test_distributions import (
-    Simplex,
-    Rplusbig,
-    Rminusbig,
-    Unit,
-    R,
-    Vector,
-    MultiSimplex,
     Circ,
+    MultiSimplex,
+    R,
+    Rminusbig,
+    Rplusbig,
+    Simplex,
     SortedVector,
+    Unit,
     UnitSortedVector,
+    Vector,
 )
-from .checks import close_to, close_to_logical
-from ..theanof import jacobian
-
 
 # some transforms (stick breaking) require additon of small slack in order to be numerically
 # stable. The minimal addable slack for float32 is higher thus we need to be less strict
diff --git a/pymc3/tests/test_tuning.py b/pymc3/tests/test_tuning.py
index ad73c39ace..1d9cf0993a 100644
--- a/pymc3/tests/test_tuning.py
+++ b/pymc3/tests/test_tuning.py
@@ -13,9 +13,12 @@
 #   limitations under the License.
 
 import numpy as np
+
 from numpy import inf
+
 from pymc3.step_methods.metropolis import tune
-from pymc3.tuning import scaling, find_MAP
+from pymc3.tuning import find_MAP, scaling
+
 from . import models
 
 
diff --git a/pymc3/tests/test_types.py b/pymc3/tests/test_types.py
index 644767f081..98153fca7c 100644
--- a/pymc3/tests/test_types.py
+++ b/pymc3/tests/test_types.py
@@ -14,16 +14,15 @@
 
 from copy import copy
 
+import numpy as np
 import theano
 
-from pymc3.sampling import sample
-from pymc3.model import Model
-from pymc3.step_methods import NUTS, Metropolis, Slice, HamiltonianMC, MLDA
 from pymc3.distributions import Normal
+from pymc3.model import Model
+from pymc3.sampling import sample
+from pymc3.step_methods import MLDA, NUTS, HamiltonianMC, Metropolis, Slice
 from pymc3.theanof import change_flags
 
-import numpy as np
-
 
 class TestType:
     samplers = (Metropolis, Slice, HamiltonianMC, NUTS)
diff --git a/pymc3/tests/test_updates.py b/pymc3/tests/test_updates.py
index 807171c6aa..371ab354b5 100644
--- a/pymc3/tests/test_updates.py
+++ b/pymc3/tests/test_updates.py
@@ -12,20 +12,22 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pytest
 import numpy as np
+import pytest
 import theano
+
 from theano.configparser import change_flags
+
 from pymc3.variational.updates import (
-    sgd,
-    momentum,
-    nesterov_momentum,
-    adagrad,
-    rmsprop,
     adadelta,
+    adagrad,
+    adagrad_window,
     adam,
     adamax,
-    adagrad_window,
+    momentum,
+    nesterov_momentum,
+    rmsprop,
+    sgd,
 )
 
 _a = theano.shared(1.0)
diff --git a/pymc3/tests/test_util.py b/pymc3/tests/test_util.py
index 63fda20457..2132de5319 100644
--- a/pymc3/tests/test_util.py
+++ b/pymc3/tests/test_util.py
@@ -12,14 +12,17 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import numpy as np
 import pytest
 
-import pymc3 as pm
-import numpy as np
 from numpy.testing import assert_almost_equal
-from .helpers import SeededTest
+
+import pymc3 as pm
+
 from pymc3.distributions.transforms import Transform
 
+from .helpers import SeededTest
+
 
 class TestTransformName:
     cases = [("var", "var_test__"), ("var_test_", "var_test__test__")]
diff --git a/pymc3/tests/test_variational_inference.py b/pymc3/tests/test_variational_inference.py
index 07437f642c..fb88649ef3 100644
--- a/pymc3/tests/test_variational_inference.py
+++ b/pymc3/tests/test_variational_inference.py
@@ -12,36 +12,34 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import pytest
 import functools
 import io
 import operator
+
 import numpy as np
+import pytest
 import theano
 import theano.tensor as tt
 
-
 import pymc3 as pm
 import pymc3.memoize
 import pymc3.util
-from pymc3.theanof import (
-    change_flags,
-    intX,
-)
+
+from pymc3.theanof import change_flags, intX
+from pymc3.variational import flows, opvi
 from pymc3.variational.approximations import (
-    MeanFieldGroup,
-    FullRankGroup,
-    NormalizingFlowGroup,
+    Empirical,
     EmpiricalGroup,
-    MeanField,
     FullRank,
+    FullRankGroup,
+    MeanField,
+    MeanFieldGroup,
     NormalizingFlow,
-    Empirical,
+    NormalizingFlowGroup,
 )
-from pymc3.variational.inference import ADVI, FullRankADVI, SVGD, NFVI, ASVGD, fit
-from pymc3.variational import flows
+from pymc3.variational.inference import ADVI, ASVGD, NFVI, SVGD, FullRankADVI, fit
 from pymc3.variational.opvi import Approximation, Group
-from pymc3.variational import opvi
+
 from . import models
 from .helpers import not_raises
 
diff --git a/pymc3/theanof.py b/pymc3/theanof.py
index c11ddae0dd..9294c0213b 100644
--- a/pymc3/theanof.py
+++ b/pymc3/theanof.py
@@ -14,7 +14,9 @@
 
 import numpy as np
 import theano
-from theano import scalar, tensor as tt
+
+from theano import scalar
+from theano import tensor as tt
 from theano.configparser import change_flags
 from theano.gof import Op
 from theano.gof.graph import inputs
@@ -22,7 +24,7 @@
 
 from .blocking import ArrayOrdering
 from .data import GeneratorAdapter
-from .vartypes import typefilter, continuous_types, int_types
+from .vartypes import continuous_types, int_types, typefilter
 
 __all__ = [
     "gradient",
diff --git a/pymc3/tuning/__init__.py b/pymc3/tuning/__init__.py
index 94330badd1..37071f76f2 100644
--- a/pymc3/tuning/__init__.py
+++ b/pymc3/tuning/__init__.py
@@ -12,5 +12,5 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+from .scaling import find_hessian, guess_scaling, trace_cov
 from .starting import find_MAP
-from .scaling import find_hessian, trace_cov, guess_scaling
diff --git a/pymc3/tuning/scaling.py b/pymc3/tuning/scaling.py
index 47aa78e21e..7484366309 100644
--- a/pymc3/tuning/scaling.py
+++ b/pymc3/tuning/scaling.py
@@ -13,10 +13,12 @@
 #   limitations under the License.
 
 import numpy as np
+
 from numpy import exp, log, sqrt
-from ..model import modelcontext, Point
+
+from ..blocking import ArrayOrdering, DictToArrayBijection
+from ..model import Point, modelcontext
 from ..theanof import hessian_diag, inputvars
-from ..blocking import DictToArrayBijection, ArrayOrdering
 from ..util import get_var_name
 
 __all__ = ["find_hessian", "trace_cov", "guess_scaling"]
diff --git a/pymc3/tuning/starting.py b/pymc3/tuning/starting.py
index 6c83af33f0..f3a25a48fb 100644
--- a/pymc3/tuning/starting.py
+++ b/pymc3/tuning/starting.py
@@ -17,21 +17,29 @@
 
 @author: johnsalvatier
 """
-from scipy.optimize import minimize
+import warnings
+
+from inspect import getargspec
+
 import numpy as np
+import theano.gradient as tg
+
+from fastprogress.fastprogress import ProgressBar, progress_bar
 from numpy import isfinite, nan_to_num
-from fastprogress.fastprogress import progress_bar
-from fastprogress.fastprogress import ProgressBar
+from scipy.optimize import minimize
+
 import pymc3 as pm
-from ..vartypes import discrete_types, typefilter
-from ..model import modelcontext, Point
-from ..theanof import inputvars
-import theano.gradient as tg
-from ..blocking import DictToArrayBijection, ArrayOrdering
-from ..util import check_start_vals, update_start_vals, get_default_varnames, get_var_name
 
-import warnings
-from inspect import getargspec
+from ..blocking import ArrayOrdering, DictToArrayBijection
+from ..model import Point, modelcontext
+from ..theanof import inputvars
+from ..util import (
+    check_start_vals,
+    get_default_varnames,
+    get_var_name,
+    update_start_vals,
+)
+from ..vartypes import discrete_types, typefilter
 
 __all__ = ["find_MAP"]
 
diff --git a/pymc3/util.py b/pymc3/util.py
index c18296b17f..54e19a6c80 100644
--- a/pymc3/util.py
+++ b/pymc3/util.py
@@ -12,18 +12,19 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-import re
 import functools
-from typing import List, Dict, Tuple, Union
+import re
 import warnings
 
+from typing import Dict, List, Tuple, Union
+
+import arviz
 import numpy as np
 import xarray
-import arviz
 
-from pymc3.exceptions import SamplingError
 from theano.tensor import TensorVariable
 
+from pymc3.exceptions import SamplingError
 
 LATEX_ESCAPE_RE = re.compile(r"(%|_|\$|#|&)", re.MULTILINE)
 
diff --git a/pymc3/variational/__init__.py b/pymc3/variational/__init__.py
index 9dbe93a94a..663fa93774 100644
--- a/pymc3/variational/__init__.py
+++ b/pymc3/variational/__init__.py
@@ -13,34 +13,50 @@
 #   limitations under the License.
 
 # commonly used
-from . import updates
+from . import (
+    approximations,
+    callbacks,
+    flows,
+    inference,
+    operators,
+    opvi,
+    test_functions,
+    updates,
+)
+from .approximations import (
+    Empirical,
+    FullRank,
+    MeanField,
+    NormalizingFlow,
+    sample_approx,
+)
+from .inference import (
+    ADVI,
+    ASVGD,
+    NFVI,
+    SVGD,
+    FullRankADVI,
+    ImplicitGradient,
+    Inference,
+    KLqp,
+    fit,
+)
+from .opvi import Approximation, Group
+
+# special
+from .stein import Stein
 from .updates import (
-    sgd,
-    apply_momentum,
-    momentum,
-    apply_nesterov_momentum,
-    adagrad_window,
-    nesterov_momentum,
-    adagrad,
-    rmsprop,
     adadelta,
+    adagrad,
+    adagrad_window,
     adam,
     adamax,
+    apply_momentum,
+    apply_nesterov_momentum,
+    momentum,
+    nesterov_momentum,
     norm_constraint,
+    rmsprop,
+    sgd,
     total_norm_constraint,
 )
-
-from . import inference
-from .inference import ADVI, FullRankADVI, SVGD, ASVGD, NFVI, Inference, KLqp, ImplicitGradient, fit
-
-from . import approximations
-from .approximations import MeanField, FullRank, Empirical, NormalizingFlow, sample_approx
-from . import opvi
-from .opvi import Group, Approximation
-
-# special
-from .stein import Stein
-from . import flows
-from . import operators
-from . import test_functions
-from . import callbacks
diff --git a/pymc3/variational/approximations.py b/pymc3/variational/approximations.py
index 4724259d27..e3bbbfb8e5 100644
--- a/pymc3/variational/approximations.py
+++ b/pymc3/variational/approximations.py
@@ -14,17 +14,19 @@
 
 import numpy as np
 import theano
+
 from theano import tensor as tt
 
 import pymc3 as pm
+
 from pymc3.distributions.dist_math import rho2sigma
-from . import opvi
-from pymc3.variational.opvi import Group, Approximation, node_property
-from pymc3.util import update_start_vals
-from pymc3.theanof import change_flags
 from pymc3.math import batched_diag
+from pymc3.theanof import change_flags
+from pymc3.util import update_start_vals
 from pymc3.variational import flows
+from pymc3.variational.opvi import Approximation, Group, node_property
 
+from . import opvi
 
 __all__ = ["MeanField", "FullRank", "Empirical", "NormalizingFlow", "sample_approx"]
 
diff --git a/pymc3/variational/flows.py b/pymc3/variational/flows.py
index 8ef7e9bff9..df63e15d76 100644
--- a/pymc3/variational/flows.py
+++ b/pymc3/variational/flows.py
@@ -14,13 +14,14 @@
 
 import numpy as np
 import theano
+
 from theano import tensor as tt
 
 from ..distributions.dist_math import rho2sigma
-from ..theanof import change_flags
 from ..memoize import WithMemoization
-from .opvi import node_property, collect_shared_to_list
+from ..theanof import change_flags
 from . import opvi
+from .opvi import collect_shared_to_list, node_property
 
 __all__ = ["Formula", "PlanarFlow", "HouseholderFlow", "RadialFlow", "LocFlow", "ScaleFlow"]
 
diff --git a/pymc3/variational/inference.py b/pymc3/variational/inference.py
index 3810759d09..b8d766f019 100644
--- a/pymc3/variational/inference.py
+++ b/pymc3/variational/inference.py
@@ -12,22 +12,25 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
+import collections
 import logging
 import warnings
-import collections
 
 import numpy as np
+
 from fastprogress.fastprogress import progress_bar
 
 import pymc3 as pm
+
 from pymc3.variational import test_functions
 from pymc3.variational.approximations import (
-    MeanField,
-    FullRank,
     Empirical,
+    FullRank,
+    MeanField,
     NormalizingFlow,
 )
 from pymc3.variational.operators import KL, KSD
+
 from . import opvi
 
 logger = logging.getLogger(__name__)
diff --git a/pymc3/variational/operators.py b/pymc3/variational/operators.py
index 7e9e94d976..92992d6977 100644
--- a/pymc3/variational/operators.py
+++ b/pymc3/variational/operators.py
@@ -13,11 +13,14 @@
 #   limitations under the License.
 
 from theano import tensor as tt
+
+import pymc3 as pm
+
 from pymc3.theanof import change_flags
-from . import opvi
-from pymc3.variational.opvi import Operator, ObjectiveFunction
+from pymc3.variational.opvi import ObjectiveFunction, Operator
 from pymc3.variational.stein import Stein
-import pymc3 as pm
+
+from . import opvi
 
 __all__ = ["KL", "KSD"]
 
diff --git a/pymc3/variational/opvi.py b/pymc3/variational/opvi.py
index b32de3807f..7e2b9bc60e 100644
--- a/pymc3/variational/opvi.py
+++ b/pymc3/variational/opvi.py
@@ -54,14 +54,16 @@
 import theano.tensor as tt
 
 import pymc3 as pm
+
 from pymc3.util import get_transformed
-from .updates import adagrad_window
-from ..blocking import ArrayOrdering, DictToArrayBijection, VarMap
+
 from ..backends import NDArray
+from ..blocking import ArrayOrdering, DictToArrayBijection, VarMap
+from ..memoize import WithMemoization, memoize
 from ..model import modelcontext
-from ..theanof import tt_rng, change_flags, identity
+from ..theanof import change_flags, identity, tt_rng
 from ..util import get_default_varnames
-from ..memoize import WithMemoization, memoize
+from .updates import adagrad_window
 
 __all__ = ["ObjectiveFunction", "Operator", "TestFunction", "Group", "Approximation"]
 
diff --git a/pymc3/variational/stein.py b/pymc3/variational/stein.py
index d610fa4da3..cf836be734 100644
--- a/pymc3/variational/stein.py
+++ b/pymc3/variational/stein.py
@@ -14,10 +14,11 @@
 
 import theano
 import theano.tensor as tt
+
+from pymc3.memoize import WithMemoization, memoize
+from pymc3.theanof import change_flags, floatX
 from pymc3.variational.opvi import node_property
 from pymc3.variational.test_functions import rbf
-from pymc3.theanof import floatX, change_flags
-from pymc3.memoize import WithMemoization, memoize
 
 __all__ = ["Stein"]
 
diff --git a/pymc3/variational/test_functions.py b/pymc3/variational/test_functions.py
index cd0ffb0ca9..90d56ad86e 100644
--- a/pymc3/variational/test_functions.py
+++ b/pymc3/variational/test_functions.py
@@ -13,9 +13,11 @@
 #   limitations under the License.
 
 from theano import tensor as tt
-from .opvi import TestFunction
+
 from pymc3.theanof import floatX
 
+from .opvi import TestFunction
+
 __all__ = ["rbf"]
 
 
diff --git a/pymc3/variational/updates.py b/pymc3/variational/updates.py
index c555dfb345..a2baa462c5 100755
--- a/pymc3/variational/updates.py
+++ b/pymc3/variational/updates.py
@@ -109,14 +109,14 @@
 Taken from the Lasagne project: http://lasagne.readthedocs.io/en/latest/
 
 """
-from functools import partial
 from collections import OrderedDict
-import numpy as np
+from functools import partial
 
+import numpy as np
 import theano
 import theano.tensor as tt
-import pymc3 as pm
 
+import pymc3 as pm
 
 __all__ = [
     "sgd",
diff --git a/pymc3/vartypes.py b/pymc3/vartypes.py
index ec28eb1145..9ddd88c21a 100644
--- a/pymc3/vartypes.py
+++ b/pymc3/vartypes.py
@@ -12,9 +12,8 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-from theano.tensor import Constant as tensor_constant
 from theano.gof.graph import Constant as graph_constant
-
+from theano.tensor import Constant as tensor_constant
 
 __all__ = [
     "bool_types",
diff --git a/scripts/check_all_tests_are_covered.py b/scripts/check_all_tests_are_covered.py
index 54221fa21b..2882f57346 100644
--- a/scripts/check_all_tests_are_covered.py
+++ b/scripts/check_all_tests_are_covered.py
@@ -7,10 +7,10 @@
 You can run it manually with `pre-commit run check-no-tests-are-ignored --all`.
 """
 
-from pathlib import Path
-
 import re
 
+from pathlib import Path
+
 if __name__ == "__main__":
     pytest_ci_job = Path(".github") / "workflows/pytest.yml"
     txt = pytest_ci_job.read_text()
diff --git a/scripts/check_toc_is_complete.py b/scripts/check_toc_is_complete.py
index ea82ab1a3a..658d6c3a72 100644
--- a/scripts/check_toc_is_complete.py
+++ b/scripts/check_toc_is_complete.py
@@ -5,10 +5,11 @@
 You can run it manually with `pre-commit run check-toc --all`.
 """
 
-from pathlib import Path
 import argparse
 import ast
 
+from pathlib import Path
+
 if __name__ == "__main__":
     toc_examples = (Path("docs") / "source/notebooks/table_of_contents_examples.js").read_text()
     toc_tutorials = (Path("docs") / "source/notebooks/table_of_contents_tutorials.js").read_text()
diff --git a/setup.py b/setup.py
index 9d5071f64b..72ff10c0a3 100755
--- a/setup.py
+++ b/setup.py
@@ -12,12 +12,13 @@
 #   See the License for the specific language governing permissions and
 #   limitations under the License.
 
-#!/usr/bin/env python
-from codecs import open
-from os.path import realpath, dirname, join
-from setuptools import setup, find_packages
 import re
 
+from codecs import open
+from os.path import dirname, join, realpath
+
+from setuptools import find_packages, setup
+
 DISTNAME = "pymc3"
 DESCRIPTION = "Probabilistic Programming in Python: Bayesian Modeling and Probabilistic Machine Learning with Theano"
 AUTHOR = "PyMC Developers"