CtxMixin (#1548)

- DRY-fy #1545 (cd30189)
- Apply the fix to two more classes with the same issue (`Domain`, `Group`)

tiledb/attribute.py

@@ -4,15 +4,15 @@
 from typing import Any, Sequence, TYPE_CHECKING, Union
 
 import tiledb.cc as lt
-from .ctx import default_ctx
+from .ctx import CtxMixin
 from .filter import FilterList, Filter
 from .util import array_type_ncells, numpy_dtype, tiledb_type_is_datetime
 
 if TYPE_CHECKING:
     from .libtiledb import Ctx
 
 
-class Attr(lt.Attribute):
+class Attr(CtxMixin, lt.Attribute):
     """
     Represents a TileDB attribute.
     """
@@ -46,15 +46,13 @@ def __init__(
         :raises: :py:exc:`tiledb.TileDBError`
 
         """
-        self._ctx = ctx or default_ctx()
-        _dtype = None
-
         if _capsule is not None:
-            return super().__init__(self._ctx, _capsule)
+            return super().__init__(ctx, _capsule)
 
         if _lt_obj is not None:
-            return super().__init__(_lt_obj)
+            return super().__init__(ctx, _lt_obj=_lt_obj)
 
+        _dtype = None
         if isinstance(dtype, str) and dtype == "ascii":
             tiledb_dtype = lt.DataType.STRING_ASCII
             _ncell = lt.TILEDB_VAR_NUM()
@@ -96,14 +94,7 @@ def __init__(
 
         var = var or False
 
-        try:
-            super().__init__(self._ctx, name, tiledb_dtype)
-        except lt.TileDBError as e:
-            # we set this here because if the super().__init__() constructor above
-            # fails, we want to check if self._ctx is None in __repr__ so we can
-            # perform a safe repr
-            self._ctx = None
-            raise lt.TileDBError(e) from None
+        super().__init__(ctx, name, tiledb_dtype)
 
         if _ncell:
             self._ncell = _ncell
@@ -180,7 +171,7 @@ def filters(self) -> FilterList:
         :raises: :py:exc:`tiledb.TileDBError`
 
         """
-        return FilterList(_lt_obj=self._filters)
+        return FilterList(ctx=self._ctx, _lt_obj=self._filters)
 
     def _get_fill(self, value, dtype) -> Any:
         if dtype in (lt.DataType.CHAR, lt.DataType.BLOB):
@@ -242,10 +233,6 @@ def isascii(self) -> bool:
         return self._tiledb_dtype == lt.DataType.STRING_ASCII
 
     def __repr__(self):
-        # use safe repr if pybind11 constructor failed
-        if self._ctx is None:
-            return object.__repr__(self)
-
         filters_str = ""
         if self.filters:
             filters_str = ", filters=FilterList(["

tiledb/ctx.py

@@ -394,6 +394,26 @@ def get_stats(self, print_out: bool = True, json: bool = False):
             return output
 
 
+class CtxMixin:
+    """
+    Base mixin class for pure Python classes that extend PyBind11 TileDB classes.
+
+    To use this class, a subclass must:
+    - Inherit from it first (i.e. `class Foo(CtxMixin, Bar)`, not `class Foo(Bar, CtxMixin)`
+    - Call super().__init__ by passing `ctx` (tiledb.Ctx or None) as first parameter and
+      - either zero or more pure Python positional parameters
+      - or a single `_lt_obj` PyBind11 parameter
+    """
+
+    def __init__(self, ctx, *args, _lt_obj=None):
+        if not ctx:
+            ctx = default_ctx()
+        super().__init__(_lt_obj or ctx, *args)
+        # we set this here because if the super().__init__() constructor above fails,
+        # we don't want to set self._ctx
+        self._ctx = ctx
+
+
 def check_ipykernel_warn_once():
     """
     This function checks if we have imported ipykernel version < 6 in the

tiledb/dimension.py

@@ -3,7 +3,7 @@
 import numpy as np
 
 import tiledb.cc as lt
-from .ctx import default_ctx
+from .ctx import CtxMixin
 from .filter import FilterList, Filter
 from .util import (
     dtype_to_tiledb,
@@ -77,7 +77,7 @@ def _tiledb_cast_domain(
     return (np_dtype(domain[0]), np_dtype(domain[1]))
 
 
-class Dim(lt.Dimension):
+class Dim(CtxMixin, lt.Dimension):
     """
     Represents a TileDB dimension.
     """
@@ -110,10 +110,8 @@ def __init__(
         :param tiledb.Ctx ctx: A TileDB Context
 
         """
-        self._ctx = ctx or default_ctx()
-
         if _lt_obj is not None:
-            return super().__init__(_lt_obj)
+            return super().__init__(ctx, _lt_obj=_lt_obj)
 
         if var is not None:
             if var and np.dtype(dtype) not in (np.str_, np.bytes_):
@@ -169,16 +167,7 @@ def __init__(
                 if tile_size_array.size != 1:
                     raise ValueError("tile extent must be a scalar")
 
-        try:
-            super().__init__(
-                self._ctx, name, dim_datatype, domain_array, tile_size_array
-            )
-        except lt.TileDBError as e:
-            # we set this here because if the super().__init__() constructor above
-            # fails, we want to check if self._ctx is None in __repr__ so we can
-            # perform a safe repr
-            self._ctx = None
-            raise lt.TileDBError(e) from None
+        super().__init__(ctx, name, dim_datatype, domain_array, tile_size_array)
 
         if filters is not None:
             if isinstance(filters, FilterList):
@@ -187,10 +176,6 @@ def __init__(
                 self._filters = FilterList(filters)
 
     def __repr__(self) -> str:
-        # use safe repr if pybind11 constructor failed
-        if self._ctx is None:
-            return object.__repr__(self)
-
         filters_str = ""
         if self.filters:
             filters_str = ", filters=FilterList(["
@@ -303,7 +288,7 @@ def filters(self) -> FilterList:
         :raises: :py:exc:`tiledb.TileDBError`
 
         """
-        return FilterList(_lt_obj=self._filters)
+        return FilterList(ctx=self._ctx, _lt_obj=self._filters)
 
     @property
     def shape(self) -> Tuple["np.generic", "np.generic"]:

tiledb/domain.py

@@ -2,7 +2,7 @@
 from typing import TYPE_CHECKING
 
 import tiledb.cc as lt
-from .ctx import default_ctx
+from .ctx import CtxMixin
 from .dimension import Dim
 from .util import numpy_dtype
 
@@ -12,7 +12,7 @@
     from .libtiledb import Ctx
 
 
-class Domain(lt.Domain):
+class Domain(CtxMixin, lt.Domain):
     """
     Represents a TileDB domain.
     """
@@ -32,15 +32,13 @@ def __init__(
         :param tiledb.Ctx ctx: A TileDB Context
 
         """
-        self._ctx = ctx or default_ctx()
-
         if _capsule is not None:
-            return super().__init__(self._ctx, _capsule)
+            return super().__init__(ctx, _capsule)
 
         if _lt_obj is not None:
-            return super().__init__(_lt_obj)
+            return super().__init__(ctx, _lt_obj=_lt_obj)
 
-        super().__init__(self._ctx)
+        super().__init__(ctx)
 
         # support passing a list of dims without splatting
         if len(dims) == 1 and isinstance(dims[0], list):
@@ -79,7 +77,7 @@ def clone_dim_with_name(dim, name):
             self._add_dim(d)
 
     def __repr__(self):
-        dims = ",\n       ".join([repr(self.dim(i)) for i in range(self.ndim)])
+        dims = ",\n       ".join(repr(self.dim(i)) for i in range(self.ndim))
         return "Domain({0!s})".format(dims)
 
     def _repr_html_(self) -> str: