diff --git a/.github/workflows/unit-tests.yaml b/.github/workflows/unit-tests.yaml
index 6884f8b6f..d32032ad9 100644
--- a/.github/workflows/unit-tests.yaml
+++ b/.github/workflows/unit-tests.yaml
@@ -43,7 +43,7 @@ jobs:
 
     - name: Test with flake8
       run: |
-        flake8 . --ignore E,F,I,SIM,C,PT,N,ASS,A,P,R,W
+        flake8 . --ignore E,I,SIM,C,PT,N,ASS,A,P,R,W,F401,F841
       if: matrix.python-version != '2.7'
 
     - name: Test with pytest
diff --git a/PyPDF2/generic.py b/PyPDF2/generic.py
index 5340353c4..8e3e28cf4 100644
--- a/PyPDF2/generic.py
+++ b/PyPDF2/generic.py
@@ -34,15 +34,14 @@
 __author__ = "Mathieu Fenniak"
 __author_email__ = "biziqe@mathieu.fenniak.net"
 
+import codecs
+import decimal
 import re
-from .utils import readNonWhitespace, RC4_encrypt, skipOverComment
-from .utils import b_, u_, chr_, ord_
-from .utils import PdfStreamError
 import warnings
-from . import filters
-from . import utils
-import decimal
-import codecs
+
+from . import filters, utils
+from .utils import (PdfStreamError, RC4_encrypt, b_, chr_, ord_,
+                    readNonWhitespace, skipOverComment, u_)
 
 ObjectPrefix = b_('/<[tf(n%')
 NumberSigns = b_('+-')
@@ -631,7 +630,6 @@ def readFromStream(stream, pdf):
                     # we found it by looking back one character further.
                     data["__streamdata__"] = data["__streamdata__"][:-1]
                 else:
-                    if debug: print(("E", e, ndstream, debugging.toHex(end)))
                     stream.seek(pos, 0)
                     raise utils.PdfReadError("Unable to find 'endstream' marker after stream at byte %s." % utils.hexStr(stream.tell()))
         else:
diff --git a/PyPDF2/merger.py b/PyPDF2/merger.py
index e362732e8..c936f85d4 100644
--- a/PyPDF2/merger.py
+++ b/PyPDF2/merger.py
@@ -27,11 +27,15 @@
 # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-from .generic import *
-from .utils import isString, str_
-from .pdf import PdfFileReader, PdfFileWriter
-from .pagerange import PageRange
 from sys import version_info
+
+from .generic import (ArrayObject, Bookmark, Destination, DictionaryObject,
+                      Field, FloatObject, NameObject, NullObject, NumberObject,
+                      TextStringObject, TreeObject, createStringObject)
+from .pagerange import PageRange
+from .pdf import PdfFileReader, PdfFileWriter
+from .utils import isString, str_
+
 if version_info < ( 3, 0 ):
     from cStringIO import StringIO
     StreamIO = StringIO
diff --git a/PyPDF2/pdf.py b/PyPDF2/pdf.py
index 7b7f08bf3..0f5504762 100644
--- a/PyPDF2/pdf.py
+++ b/PyPDF2/pdf.py
@@ -41,12 +41,13 @@
 __maintainer__ = "Phaseit, Inc."
 __maintainer_email = "PyPDF2@phaseit.net"
 
-import string
 import math
+import string
 import struct
 import sys
 import uuid
 from sys import version_info
+
 if version_info < ( 3, 0 ):
     from cStringIO import StringIO
 else:
@@ -57,13 +58,18 @@
 else:
     from io import BytesIO
 
-from . import filters
-from . import utils
-import warnings
 import codecs
-from .generic import *
-from .utils import readNonWhitespace, readUntilWhitespace, ConvertFunctionsToVirtualList
-from .utils import isString, b_, u_, ord_, str_, formatWarning
+import warnings
+
+from . import filters, utils
+from .generic import (ArrayObject, BooleanObject, ByteStringObject,
+                      DecodedStreamObject, Destination, DictionaryObject,
+                      Field, FloatObject, IndirectObject, NameObject,
+                      NullObject, NumberObject, RectangleObject, StreamObject,
+                      TextStringObject, TreeObject, createStringObject,
+                      readObject)
+from .utils import (ConvertFunctionsToVirtualList, b_, formatWarning, isString,
+                    ord_, readNonWhitespace, readUntilWhitespace, str_, u_)
 
 if version_info < ( 2, 4 ):
    from sets import ImmutableSet as frozenset
@@ -72,7 +78,6 @@
     from md5 import md5
 else:
     from hashlib import md5
-import uuid
 
 
 class PdfFileWriter(object):
@@ -406,7 +411,8 @@ def encrypt(self, user_pwd, owner_pwd = None, use_128bit = True):
             encryption.  When false, 40bit encryption will be used.  By default,
             this flag is on.
         """
-        import time, random
+        import random
+        import time
         if owner_pwd == None:
             owner_pwd = user_pwd
         if use_128bit:
diff --git a/PyPDF2/utils.py b/PyPDF2/utils.py
index e104c394e..81abf0eb2 100644
--- a/PyPDF2/utils.py
+++ b/PyPDF2/utils.py
@@ -45,7 +45,7 @@
 
 bytes_type = type(bytes()) # Works the same in Python 2.X and 3.X
 string_type = getattr(builtins, "unicode", str)
-int_types = (int, long) if sys.version_info[0] < 3 else (int,)
+int_types = (int, long) if sys.version_info[0] < 3 else (int,)  # noqa
 
 
 # Make basic type tests more consistent
@@ -252,7 +252,7 @@ def b_(s):
 
 def u_(s):
     if sys.version_info[0] < 3:
-        return unicode(s, 'unicode_escape')
+        return unicode(s, 'unicode_escape')  # noqa
     else:
         return s