diff --git a/.flake8 b/.flake8
index 553473f1fbe0..4cbcd7e2881f 100644
--- a/.flake8
+++ b/.flake8
@@ -49,39 +49,21 @@ per-file-ignores =
     lib/matplotlib/_cm.py: E122, E202, E203, E302
     lib/matplotlib/_mathtext.py: E221, E251
     lib/matplotlib/_mathtext_data.py: E122, E203, E261
-    lib/matplotlib/animation.py: F401
     lib/matplotlib/_animation_data.py: E501
     lib/matplotlib/axes/__init__.py: F401, F403
-    lib/matplotlib/axes/_axes.py: F401
-    lib/matplotlib/backends/backend_*.py: F401
+    lib/matplotlib/backends/backend_template.py: F401
     lib/matplotlib/backends/qt_editor/formlayout.py: F401, F403
-    lib/matplotlib/cbook/__init__.py: F401
-    lib/matplotlib/cbook/deprecation.py: F401
     lib/matplotlib/font_manager.py: E501
     lib/matplotlib/image.py: F401, F403
-    lib/matplotlib/lines.py: F401
     lib/matplotlib/mathtext.py: E221, E251
     lib/matplotlib/pylab.py: F401, F403
     lib/matplotlib/pyplot.py: F401, F811
-    lib/matplotlib/style/__init__.py: F401
-    lib/matplotlib/testing/conftest.py: F401
-    lib/matplotlib/tests/conftest.py: F401
-    lib/matplotlib/tests/test_backend_qt.py: F401
     lib/matplotlib/tests/test_mathtext.py: E501
-    lib/matplotlib/text.py: F401
     lib/matplotlib/transforms.py: E201, E202, E203
-    lib/matplotlib/tri/__init__.py: F401, F403
     lib/matplotlib/tri/triinterpolate.py: E201, E221
-    lib/mpl_toolkits/axes_grid/*: F401, F403
-    lib/mpl_toolkits/axes_grid1/__init__.py: F401
     lib/mpl_toolkits/axes_grid1/axes_size.py: E272
     lib/mpl_toolkits/axisartist/__init__.py: F401
     lib/mpl_toolkits/axisartist/angle_helper.py: E221
-    lib/mpl_toolkits/axisartist/axes_divider.py: F401
-    lib/mpl_toolkits/axisartist/axes_rgb.py: F401
-    lib/mpl_toolkits/axisartist/axislines.py: F401
-    lib/mpl_toolkits/mplot3d/__init__.py: F401
-    lib/mpl_toolkits/tests/conftest.py: F401
     lib/pylab.py: F401, F403
 
     doc/conf.py: E402
diff --git a/doc/api/tri_api.rst b/doc/api/tri_api.rst
index fdf123c03908..0b4e046eec08 100644
--- a/doc/api/tri_api.rst
+++ b/doc/api/tri_api.rst
@@ -2,7 +2,9 @@
 ``matplotlib.tri``
 ******************
 
-.. automodule:: matplotlib.tri
+Unstructured triangular grid functions.
+
+.. py:module:: matplotlib.tri
 
 .. autoclass:: matplotlib.tri.Triangulation
     :members:
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
index 454b9a93d981..01cb9501d30a 100644
--- a/lib/matplotlib/axes/_axes.py
+++ b/lib/matplotlib/axes/_axes.py
@@ -12,7 +12,7 @@
 import matplotlib.collections as mcoll
 import matplotlib.colors as mcolors
 import matplotlib.contour as mcontour
-import matplotlib.dates  # Register date unit converter as side-effect.
+import matplotlib.dates  # noqa # Register date unit converter as side-effect.
 import matplotlib.image as mimage
 import matplotlib.legend as mlegend
 import matplotlib.lines as mlines
diff --git a/lib/matplotlib/backends/backend_gtk3cairo.py b/lib/matplotlib/backends/backend_gtk3cairo.py
index 590daf8357dc..49215510c178 100644
--- a/lib/matplotlib/backends/backend_gtk3cairo.py
+++ b/lib/matplotlib/backends/backend_gtk3cairo.py
@@ -1,6 +1,6 @@
 from contextlib import nullcontext
 
-from .backend_cairo import (
+from .backend_cairo import (  # noqa
     FigureCanvasCairo, _RendererGTKCairo as RendererGTK3Cairo)
 from .backend_gtk3 import Gtk, FigureCanvasGTK3, _BackendGTK3
 
diff --git a/lib/matplotlib/backends/backend_gtk4.py b/lib/matplotlib/backends/backend_gtk4.py
index b92a73b5418d..41b028e6620a 100644
--- a/lib/matplotlib/backends/backend_gtk4.py
+++ b/lib/matplotlib/backends/backend_gtk4.py
@@ -6,7 +6,7 @@
 from matplotlib import _api, backend_tools, cbook
 from matplotlib.backend_bases import (
     FigureCanvasBase, ToolContainerBase,
-    CloseEvent, KeyEvent, LocationEvent, MouseEvent, ResizeEvent)
+    KeyEvent, LocationEvent, MouseEvent, ResizeEvent)
 
 try:
     import gi
@@ -22,7 +22,7 @@
     # auto-backend selection logic correctly skips.
     raise ImportError from e
 
-from gi.repository import Gio, GLib, GObject, Gtk, Gdk, GdkPixbuf
+from gi.repository import Gio, GLib, Gtk, Gdk, GdkPixbuf
 from . import _backend_gtk
 from ._backend_gtk import (
     _BackendGTK, _FigureManagerGTK, _NavigationToolbar2GTK,
diff --git a/lib/matplotlib/backends/backend_gtk4cairo.py b/lib/matplotlib/backends/backend_gtk4cairo.py
index 697884174be3..83cbd081c26d 100644
--- a/lib/matplotlib/backends/backend_gtk4cairo.py
+++ b/lib/matplotlib/backends/backend_gtk4cairo.py
@@ -1,6 +1,6 @@
 from contextlib import nullcontext
 
-from .backend_cairo import (
+from .backend_cairo import (  # noqa
     FigureCanvasCairo, _RendererGTKCairo as RendererGTK4Cairo)
 from .backend_gtk4 import Gtk, FigureCanvasGTK4, _BackendGTK4
 
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
index 766492118c97..c3b900a97399 100644
--- a/lib/matplotlib/backends/backend_pgf.py
+++ b/lib/matplotlib/backends/backend_pgf.py
@@ -1,4 +1,3 @@
-import atexit
 import codecs
 import datetime
 import functools
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 0ce2a20360da..de3747f056a7 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -8,7 +8,6 @@
 import functools
 from io import StringIO
 import logging
-import math
 import os
 import pathlib
 import re
@@ -22,8 +21,7 @@
 from matplotlib import _api, cbook, _path, _text_helpers
 from matplotlib._afm import AFM
 from matplotlib.backend_bases import (
-    _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase,
-    RendererBase)
+    _Backend, FigureCanvasBase, FigureManagerBase, RendererBase)
 from matplotlib.cbook import is_writable_file_like, file_requires_unicode
 from matplotlib.font_manager import get_font
 from matplotlib.ft2font import LOAD_NO_HINTING, LOAD_NO_SCALE, FT2Font
diff --git a/lib/matplotlib/backends/backend_qt.py b/lib/matplotlib/backends/backend_qt.py
index fd78ed1fce8d..845e5bc2063c 100644
--- a/lib/matplotlib/backends/backend_qt.py
+++ b/lib/matplotlib/backends/backend_qt.py
@@ -1,5 +1,4 @@
 import functools
-import operator
 import os
 import sys
 import traceback
diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
index b9d5f5eb2644..04c5af765513 100644
--- a/lib/matplotlib/cbook/__init__.py
+++ b/lib/matplotlib/cbook/__init__.py
@@ -22,7 +22,6 @@
 import time
 import traceback
 import types
-import warnings
 import weakref
 
 import numpy as np
diff --git a/lib/matplotlib/lines.py b/lib/matplotlib/lines.py
index fffdf1896ffd..c229c0b715cc 100644
--- a/lib/matplotlib/lines.py
+++ b/lib/matplotlib/lines.py
@@ -21,7 +21,7 @@
 # Imported here for backward compatibility, even though they don't
 # really belong.
 from . import _path
-from .markers import (
+from .markers import (  # noqa
     CARETLEFT, CARETRIGHT, CARETUP, CARETDOWN,
     CARETLEFTBASE, CARETRIGHTBASE, CARETUPBASE, CARETDOWNBASE,
     TICKLEFT, TICKRIGHT, TICKUP, TICKDOWN)
diff --git a/lib/matplotlib/style/__init__.py b/lib/matplotlib/style/__init__.py
index 42d050d22cd0..488c6d6ae1ec 100644
--- a/lib/matplotlib/style/__init__.py
+++ b/lib/matplotlib/style/__init__.py
@@ -1 +1,4 @@
-from .core import use, context, available, library, reload_library
+from .core import available, context, library, reload_library, use
+
+
+__all__ = ["available", "context", "library", "reload_library", "use"]
diff --git a/lib/matplotlib/tests/conftest.py b/lib/matplotlib/tests/conftest.py
index 06c6d150f31b..54a1bc6cae94 100644
--- a/lib/matplotlib/tests/conftest.py
+++ b/lib/matplotlib/tests/conftest.py
@@ -1,3 +1,2 @@
-from matplotlib.testing.conftest import (mpl_test_settings,
-                                         pytest_configure, pytest_unconfigure,
-                                         pd, xr)
+from matplotlib.testing.conftest import (  # noqa
+    mpl_test_settings, pytest_configure, pytest_unconfigure, pd, xr)
diff --git a/lib/matplotlib/tests/test_backend_qt.py b/lib/matplotlib/tests/test_backend_qt.py
index 9f8b09fd2cb9..14a9283ef480 100644
--- a/lib/matplotlib/tests/test_backend_qt.py
+++ b/lib/matplotlib/tests/test_backend_qt.py
@@ -18,7 +18,7 @@
 
 
 try:
-    from matplotlib.backends.qt_compat import QtGui, QtWidgets
+    from matplotlib.backends.qt_compat import QtGui, QtWidgets  # noqa
     from matplotlib.backends.qt_editor import _formlayout
 except ImportError:
     pytestmark = pytest.mark.skip('No usable Qt bindings')
@@ -87,7 +87,7 @@ def _test_sigint_impl(backend, target_name, kwargs):
     import threading
 
     plt.switch_backend(backend)
-    from matplotlib.backends.qt_compat import QtCore
+    from matplotlib.backends.qt_compat import QtCore  # noqa
 
     def interrupter():
         if sys.platform == 'win32':
@@ -138,10 +138,9 @@ def test_sigint(target, kwargs):
 
 def _test_other_signal_before_sigint_impl(backend, target_name, kwargs):
     import signal
-    import sys
     import matplotlib.pyplot as plt
     plt.switch_backend(backend)
-    from matplotlib.backends.qt_compat import QtCore
+    from matplotlib.backends.qt_compat import QtCore  # noqa
 
     target = getattr(plt, target_name)
 
@@ -498,7 +497,7 @@ def test_form_widget_get_with_datetime_and_date_fields():
 def _test_enums_impl():
     import sys
 
-    from matplotlib.backends.qt_compat import _enum, _to_int, QtCore
+    from matplotlib.backends.qt_compat import _enum, _to_int
     from matplotlib.backend_bases import cursors, MouseButton
 
     _enum("QtGui.QDoubleValidator.State").Acceptable
diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
index a59dde4706d7..3c998d540c48 100644
--- a/lib/matplotlib/text.py
+++ b/lib/matplotlib/text.py
@@ -15,7 +15,7 @@
 from .artist import Artist
 from .font_manager import FontProperties
 from .patches import FancyArrowPatch, FancyBboxPatch, Rectangle
-from .textpath import TextPath  # Unused, but imported by others.
+from .textpath import TextPath  # noqa # Unused, but imported by others.
 from .transforms import (
     Affine2D, Bbox, BboxBase, BboxTransformTo, IdentityTransform, Transform)
 
diff --git a/lib/matplotlib/tri/__init__.py b/lib/matplotlib/tri/__init__.py
index 7ff2b326920b..4185452c0123 100644
--- a/lib/matplotlib/tri/__init__.py
+++ b/lib/matplotlib/tri/__init__.py
@@ -2,11 +2,22 @@
 Unstructured triangular grid functions.
 """
 
-from .triangulation import *
-from .tricontour import *
-from .tritools import *
-from .trifinder import *
-from .triinterpolate import *
-from .trirefine import *
-from .tripcolor import *
-from .triplot import *
+from .triangulation import Triangulation
+from .tricontour import TriContourSet, tricontour, tricontourf
+from .trifinder import TriFinder, TrapezoidMapTriFinder
+from .triinterpolate import (TriInterpolator, LinearTriInterpolator,
+                             CubicTriInterpolator)
+from .tripcolor import tripcolor
+from .triplot import triplot
+from .trirefine import TriRefiner, UniformTriRefiner
+from .tritools import TriAnalyzer
+
+
+__all__ = ["Triangulation",
+           "TriContourSet", "tricontour", "tricontourf",
+           "TriFinder", "TrapezoidMapTriFinder",
+           "TriInterpolator", "LinearTriInterpolator", "CubicTriInterpolator",
+           "tripcolor",
+           "triplot",
+           "TriRefiner", "UniformTriRefiner",
+           "TriAnalyzer"]
diff --git a/lib/mpl_toolkits/axes_grid1/__init__.py b/lib/mpl_toolkits/axes_grid1/__init__.py
index 0f359c9e01f3..c55302485e3f 100644
--- a/lib/mpl_toolkits/axes_grid1/__init__.py
+++ b/lib/mpl_toolkits/axes_grid1/__init__.py
@@ -1,5 +1,10 @@
 from . import axes_size as Size
 from .axes_divider import Divider, SubplotDivider, make_axes_locatable
-from .axes_grid import Grid, ImageGrid, AxesGrid
+from .axes_grid import AxesGrid, Grid, ImageGrid
 
 from .parasite_axes import host_subplot, host_axes
+
+__all__ = ["Size",
+           "Divider", "SubplotDivider", "make_axes_locatable",
+           "AxesGrid", "Grid", "ImageGrid",
+           "host_subplot", "host_axes"]
diff --git a/lib/mpl_toolkits/axisartist/axes_divider.py b/lib/mpl_toolkits/axisartist/axes_divider.py
index 3b177838f896..a01d4e27df93 100644
--- a/lib/mpl_toolkits/axisartist/axes_divider.py
+++ b/lib/mpl_toolkits/axisartist/axes_divider.py
@@ -1,2 +1,2 @@
-from mpl_toolkits.axes_grid1.axes_divider import (
+from mpl_toolkits.axes_grid1.axes_divider import (  # noqa
     Divider, AxesLocator, SubplotDivider, AxesDivider, make_axes_locatable)
diff --git a/lib/mpl_toolkits/axisartist/axes_rgb.py b/lib/mpl_toolkits/axisartist/axes_rgb.py
index 8c1d24bc3787..22d778654b25 100644
--- a/lib/mpl_toolkits/axisartist/axes_rgb.py
+++ b/lib/mpl_toolkits/axisartist/axes_rgb.py
@@ -1,4 +1,5 @@
-from mpl_toolkits.axes_grid1.axes_rgb import make_rgb_axes, RGBAxes as _RGBAxes
+from mpl_toolkits.axes_grid1.axes_rgb import (  # noqa
+    make_rgb_axes, RGBAxes as _RGBAxes)
 from .axislines import Axes
 
 
diff --git a/lib/mpl_toolkits/axisartist/axislines.py b/lib/mpl_toolkits/axisartist/axislines.py
index d62ab7eb0b23..ff1d063d3fb0 100644
--- a/lib/mpl_toolkits/axisartist/axislines.py
+++ b/lib/mpl_toolkits/axisartist/axislines.py
@@ -46,7 +46,7 @@
 import matplotlib.axes as maxes
 from matplotlib.path import Path
 from mpl_toolkits.axes_grid1 import mpl_axes
-from .axisline_style import AxislineStyle
+from .axisline_style import AxislineStyle  # noqa
 from .axis_artist import AxisArtist, GridlinesCollection
 
 
diff --git a/lib/mpl_toolkits/mplot3d/__init__.py b/lib/mpl_toolkits/mplot3d/__init__.py
index 30e682aea018..a089fbd6b70e 100644
--- a/lib/mpl_toolkits/mplot3d/__init__.py
+++ b/lib/mpl_toolkits/mplot3d/__init__.py
@@ -1 +1,3 @@
 from .axes3d import Axes3D
+
+__all__ = ['Axes3D']
diff --git a/lib/mpl_toolkits/tests/conftest.py b/lib/mpl_toolkits/tests/conftest.py
index 1b48dac4100d..61c2de3e07ba 100644
--- a/lib/mpl_toolkits/tests/conftest.py
+++ b/lib/mpl_toolkits/tests/conftest.py
@@ -1,2 +1,2 @@
-from matplotlib.testing.conftest import (mpl_test_settings,
+from matplotlib.testing.conftest import (mpl_test_settings,  # noqa
                                          pytest_configure, pytest_unconfigure)