From f04a33ae1a2b0518dcbc66d199b0cce1fda9446d Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Tue, 10 Jul 2018 15:24:19 -0400
Subject: [PATCH 1/2] Remove unused imports from examples.

---
 examples/event_handling/ginput_manual_clabel_sgskip.py       | 5 +----
 examples/images_contours_and_fields/contour_label_demo.py    | 1 -
 examples/images_contours_and_fields/figimage_demo.py         | 1 -
 examples/images_contours_and_fields/quadmesh_demo.py         | 2 +-
 examples/images_contours_and_fields/quiver_demo.py           | 1 -
 examples/lines_bars_and_markers/scatter_symbol.py            | 1 -
 examples/misc/load_converter.py                              | 1 -
 examples/misc/plotfile_demo.py                               | 2 --
 examples/misc/transoffset.py                                 | 1 -
 examples/mplot3d/surface3d_3.py                              | 1 -
 examples/pyplots/fig_axes_customize_simple.py                | 2 +-
 examples/pyplots/fig_x.py                                    | 1 -
 examples/shapes_and_collections/patch_collection.py          | 1 -
 examples/specialty_plots/sankey_basics.py                    | 2 +-
 examples/specialty_plots/sankey_links.py                     | 2 --
 examples/statistics/violinplot.py                            | 1 -
 examples/subplots_axes_and_figures/figure_title.py           | 1 -
 examples/tests/backend_driver_sgskip.py                      | 1 -
 examples/text_labels_and_annotations/date.py                 | 1 -
 examples/text_labels_and_annotations/fonts_demo_kw.py        | 2 --
 examples/text_labels_and_annotations/mathtext_examples.py    | 1 -
 examples/text_labels_and_annotations/text_alignment.py       | 2 --
 examples/text_labels_and_annotations/usetex_baseline_test.py | 1 -
 examples/units/basic_units.py                                | 1 -
 examples/user_interfaces/embedding_in_wx3_sgskip.py          | 5 -----
 examples/user_interfaces/mpl_with_glade3_sgskip.py           | 1 -
 examples/userdemo/connectionstyle_demo.py                    | 1 -
 examples/widgets/menu.py                                     | 1 -
 28 files changed, 4 insertions(+), 39 deletions(-)

diff --git a/examples/event_handling/ginput_manual_clabel_sgskip.py b/examples/event_handling/ginput_manual_clabel_sgskip.py
index abe1e345d86b..96104cace49d 100644
--- a/examples/event_handling/ginput_manual_clabel_sgskip.py
+++ b/examples/event_handling/ginput_manual_clabel_sgskip.py
@@ -14,12 +14,9 @@
 
 """
 
-
 import time
-import matplotlib
+
 import numpy as np
-import matplotlib.cm as cm
-import matplotlib.mlab as mlab
 import matplotlib.pyplot as plt
 
 
diff --git a/examples/images_contours_and_fields/contour_label_demo.py b/examples/images_contours_and_fields/contour_label_demo.py
index af26ab997c87..f09a7f6a141d 100644
--- a/examples/images_contours_and_fields/contour_label_demo.py
+++ b/examples/images_contours_and_fields/contour_label_demo.py
@@ -12,7 +12,6 @@
 
 import matplotlib
 import numpy as np
-import matplotlib.cm as cm
 import matplotlib.ticker as ticker
 import matplotlib.pyplot as plt
 
diff --git a/examples/images_contours_and_fields/figimage_demo.py b/examples/images_contours_and_fields/figimage_demo.py
index b2ce013d77a5..ef805576cae0 100644
--- a/examples/images_contours_and_fields/figimage_demo.py
+++ b/examples/images_contours_and_fields/figimage_demo.py
@@ -8,7 +8,6 @@
 """
 import numpy as np
 import matplotlib
-import matplotlib.cm as cm
 import matplotlib.pyplot as plt
 
 
diff --git a/examples/images_contours_and_fields/quadmesh_demo.py b/examples/images_contours_and_fields/quadmesh_demo.py
index 0e517a886a10..5488ddd83637 100644
--- a/examples/images_contours_and_fields/quadmesh_demo.py
+++ b/examples/images_contours_and_fields/quadmesh_demo.py
@@ -11,7 +11,7 @@
 
 import copy
 
-from matplotlib import cm, colors, pyplot as plt
+from matplotlib import cm, pyplot as plt
 import numpy as np
 
 n = 12
diff --git a/examples/images_contours_and_fields/quiver_demo.py b/examples/images_contours_and_fields/quiver_demo.py
index 7c1711710076..696b0a50ad7e 100644
--- a/examples/images_contours_and_fields/quiver_demo.py
+++ b/examples/images_contours_and_fields/quiver_demo.py
@@ -13,7 +13,6 @@
 """
 import matplotlib.pyplot as plt
 import numpy as np
-from numpy import ma
 
 X, Y = np.meshgrid(np.arange(0, 2 * np.pi, .2), np.arange(0, 2 * np.pi, .2))
 U = np.cos(X)
diff --git a/examples/lines_bars_and_markers/scatter_symbol.py b/examples/lines_bars_and_markers/scatter_symbol.py
index 3d04490c189e..d99b6a80a740 100644
--- a/examples/lines_bars_and_markers/scatter_symbol.py
+++ b/examples/lines_bars_and_markers/scatter_symbol.py
@@ -8,7 +8,6 @@
 """
 import matplotlib.pyplot as plt
 import numpy as np
-import matplotlib
 
 # Fixing random state for reproducibility
 np.random.seed(19680801)
diff --git a/examples/misc/load_converter.py b/examples/misc/load_converter.py
index 33a482cb27b7..9488972cae87 100644
--- a/examples/misc/load_converter.py
+++ b/examples/misc/load_converter.py
@@ -7,7 +7,6 @@
 import numpy as np
 import matplotlib.pyplot as plt
 import matplotlib.cbook as cbook
-import matplotlib.dates as mdates
 from matplotlib.dates import bytespdate2num
 
 datafile = cbook.get_sample_data('msft.csv', asfileobj=False)
diff --git a/examples/misc/plotfile_demo.py b/examples/misc/plotfile_demo.py
index b927b4870add..94bd1bd9b2bb 100644
--- a/examples/misc/plotfile_demo.py
+++ b/examples/misc/plotfile_demo.py
@@ -6,8 +6,6 @@
 Example use of ``plotfile`` to plot data directly from a file.
 """
 import matplotlib.pyplot as plt
-import numpy as np
-
 import matplotlib.cbook as cbook
 
 fname = cbook.get_sample_data('msft.csv', asfileobj=False)
diff --git a/examples/misc/transoffset.py b/examples/misc/transoffset.py
index 127ca6bf6769..7328ce2103f3 100644
--- a/examples/misc/transoffset.py
+++ b/examples/misc/transoffset.py
@@ -23,7 +23,6 @@
 import matplotlib.transforms as mtransforms
 import numpy as np
 
-from matplotlib.transforms import offset_copy
 
 xs = np.arange(7)
 ys = xs**2
diff --git a/examples/mplot3d/surface3d_3.py b/examples/mplot3d/surface3d_3.py
index 06ab93ab0a2c..bef4e41acf43 100644
--- a/examples/mplot3d/surface3d_3.py
+++ b/examples/mplot3d/surface3d_3.py
@@ -8,7 +8,6 @@
 
 from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.pyplot as plt
-from matplotlib import cm
 from matplotlib.ticker import LinearLocator
 import numpy as np
 
diff --git a/examples/pyplots/fig_axes_customize_simple.py b/examples/pyplots/fig_axes_customize_simple.py
index 50c2411bfcb8..47d8eafbc647 100644
--- a/examples/pyplots/fig_axes_customize_simple.py
+++ b/examples/pyplots/fig_axes_customize_simple.py
@@ -5,7 +5,7 @@
 
 Customize the background, labels and ticks of a simple plot.
 """
-import numpy as np
+
 import matplotlib.pyplot as plt
 
 ###############################################################################
diff --git a/examples/pyplots/fig_x.py b/examples/pyplots/fig_x.py
index 4e5d120a9a9b..d8a8c1dfaa3d 100644
--- a/examples/pyplots/fig_x.py
+++ b/examples/pyplots/fig_x.py
@@ -5,7 +5,6 @@
 
 Add lines to a figure (without axes).
 """
-import numpy as np
 import matplotlib.pyplot as plt
 import matplotlib.lines as lines
 
diff --git a/examples/shapes_and_collections/patch_collection.py b/examples/shapes_and_collections/patch_collection.py
index f86d59ea65b2..05e343465ffe 100644
--- a/examples/shapes_and_collections/patch_collection.py
+++ b/examples/shapes_and_collections/patch_collection.py
@@ -8,7 +8,6 @@
 """
 
 import numpy as np
-import matplotlib
 from matplotlib.patches import Circle, Wedge, Polygon
 from matplotlib.collections import PatchCollection
 import matplotlib.pyplot as plt
diff --git a/examples/specialty_plots/sankey_basics.py b/examples/specialty_plots/sankey_basics.py
index abfd913e193b..f625a59a8c45 100644
--- a/examples/specialty_plots/sankey_basics.py
+++ b/examples/specialty_plots/sankey_basics.py
@@ -5,7 +5,7 @@
 
 Demonstrate the Sankey class by producing three basic diagrams.
 """
-import numpy as np
+
 import matplotlib.pyplot as plt
 
 from matplotlib.sankey import Sankey
diff --git a/examples/specialty_plots/sankey_links.py b/examples/specialty_plots/sankey_links.py
index 7221d3592058..61dfc06d41b0 100644
--- a/examples/specialty_plots/sankey_links.py
+++ b/examples/specialty_plots/sankey_links.py
@@ -6,8 +6,6 @@
 Demonstrate/test the Sankey class by producing a long chain of connections.
 """
 
-from itertools import cycle
-
 import matplotlib.pyplot as plt
 from matplotlib.sankey import Sankey
 
diff --git a/examples/statistics/violinplot.py b/examples/statistics/violinplot.py
index 03640bc56272..667f23e2a308 100644
--- a/examples/statistics/violinplot.py
+++ b/examples/statistics/violinplot.py
@@ -16,7 +16,6 @@
 have a great section: http://scikit-learn.org/stable/modules/density.html
 """
 
-import random
 import numpy as np
 import matplotlib.pyplot as plt
 
diff --git a/examples/subplots_axes_and_figures/figure_title.py b/examples/subplots_axes_and_figures/figure_title.py
index cb96d5bacde9..1c54c3887be7 100644
--- a/examples/subplots_axes_and_figures/figure_title.py
+++ b/examples/subplots_axes_and_figures/figure_title.py
@@ -5,7 +5,6 @@
 
 Create a figure with separate subplot titles and a centered figure title.
 """
-from matplotlib.font_manager import FontProperties
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/tests/backend_driver_sgskip.py b/examples/tests/backend_driver_sgskip.py
index acbd99ab6ed2..8878c6273bce 100644
--- a/examples/tests/backend_driver_sgskip.py
+++ b/examples/tests/backend_driver_sgskip.py
@@ -357,7 +357,6 @@ def drive(backend, directories, python=['python'], switches=[]):
     # Clear the destination directory for the examples
     path = backend
     if os.path.exists(path):
-        import glob
         for fname in os.listdir(path):
             os.unlink(os.path.join(path, fname))
     else:
diff --git a/examples/text_labels_and_annotations/date.py b/examples/text_labels_and_annotations/date.py
index 383db6353e13..90e9f94a511e 100644
--- a/examples/text_labels_and_annotations/date.py
+++ b/examples/text_labels_and_annotations/date.py
@@ -16,7 +16,6 @@
 :class:`numpy.datetime64` objects.
 """
 
-import datetime
 import numpy as np
 import matplotlib.pyplot as plt
 import matplotlib.dates as mdates
diff --git a/examples/text_labels_and_annotations/fonts_demo_kw.py b/examples/text_labels_and_annotations/fonts_demo_kw.py
index f323570cada5..bfcec95f93f2 100644
--- a/examples/text_labels_and_annotations/fonts_demo_kw.py
+++ b/examples/text_labels_and_annotations/fonts_demo_kw.py
@@ -8,9 +8,7 @@
 See :doc:`fonts_demo` to achieve the same effect using setters.
 """
 
-from matplotlib.font_manager import FontProperties
 import matplotlib.pyplot as plt
-import numpy as np
 
 plt.subplot(111, facecolor='w')
 alignment = {'horizontalalignment': 'center', 'verticalalignment': 'baseline'}
diff --git a/examples/text_labels_and_annotations/mathtext_examples.py b/examples/text_labels_and_annotations/mathtext_examples.py
index eec403d3c531..6272099819f5 100644
--- a/examples/text_labels_and_annotations/mathtext_examples.py
+++ b/examples/text_labels_and_annotations/mathtext_examples.py
@@ -9,7 +9,6 @@
 import subprocess
 import sys
 import re
-import gc
 
 # Selection of features following "Writing mathematical expressions" tutorial
 mathtext_titles = {
diff --git a/examples/text_labels_and_annotations/text_alignment.py b/examples/text_labels_and_annotations/text_alignment.py
index 2503440c3277..e92984098c92 100644
--- a/examples/text_labels_and_annotations/text_alignment.py
+++ b/examples/text_labels_and_annotations/text_alignment.py
@@ -9,8 +9,6 @@
 """
 
 import matplotlib.pyplot as plt
-from matplotlib.lines import Line2D
-from matplotlib.patches import Rectangle
 
 # Build a rectangle in axes coords
 left, width = .25, .5
diff --git a/examples/text_labels_and_annotations/usetex_baseline_test.py b/examples/text_labels_and_annotations/usetex_baseline_test.py
index 0a72afab63e2..3aa08103bbb5 100644
--- a/examples/text_labels_and_annotations/usetex_baseline_test.py
+++ b/examples/text_labels_and_annotations/usetex_baseline_test.py
@@ -5,7 +5,6 @@
 
 """
 
-import matplotlib
 import matplotlib.pyplot as plt
 import matplotlib.axes as maxes
 
diff --git a/examples/units/basic_units.py b/examples/units/basic_units.py
index 826f543e9c3d..67ffa36f6fac 100644
--- a/examples/units/basic_units.py
+++ b/examples/units/basic_units.py
@@ -11,7 +11,6 @@
 
 import matplotlib.units as units
 import matplotlib.ticker as ticker
-from matplotlib.axes import Axes
 from matplotlib.cbook import iterable
 
 
diff --git a/examples/user_interfaces/embedding_in_wx3_sgskip.py b/examples/user_interfaces/embedding_in_wx3_sgskip.py
index 5a3d1a7aac85..fcb69f0a910b 100644
--- a/examples/user_interfaces/embedding_in_wx3_sgskip.py
+++ b/examples/user_interfaces/embedding_in_wx3_sgskip.py
@@ -21,11 +21,6 @@
 Thanks to matplotlib and wx teams for creating such great software!
 """
 
-
-import sys
-import time
-import os
-import gc
 import matplotlib
 import matplotlib.cm as cm
 import matplotlib.cbook as cbook
diff --git a/examples/user_interfaces/mpl_with_glade3_sgskip.py b/examples/user_interfaces/mpl_with_glade3_sgskip.py
index ffdf22e32ce0..3329bc342da9 100644
--- a/examples/user_interfaces/mpl_with_glade3_sgskip.py
+++ b/examples/user_interfaces/mpl_with_glade3_sgskip.py
@@ -12,7 +12,6 @@
 from gi.repository import Gtk
 
 from matplotlib.figure import Figure
-from matplotlib.axes import Subplot
 from matplotlib.backends.backend_gtk3agg import (
     FigureCanvasGTK3Agg as FigureCanvas)
 import numpy as np
diff --git a/examples/userdemo/connectionstyle_demo.py b/examples/userdemo/connectionstyle_demo.py
index 4c8abe22e4a5..1ea2bf5fe8fd 100644
--- a/examples/userdemo/connectionstyle_demo.py
+++ b/examples/userdemo/connectionstyle_demo.py
@@ -6,7 +6,6 @@
 """
 
 import matplotlib.pyplot as plt
-import matplotlib.patches as mpatches
 
 
 fig, axs = plt.subplots(3, 5, figsize=(8, 4.8))
diff --git a/examples/widgets/menu.py b/examples/widgets/menu.py
index a099b1fc92ff..fa5e3a54ace0 100644
--- a/examples/widgets/menu.py
+++ b/examples/widgets/menu.py
@@ -5,7 +5,6 @@
 
 """
 import numpy as np
-import matplotlib
 import matplotlib.colors as colors
 import matplotlib.patches as patches
 import matplotlib.mathtext as mathtext

From bed25a85abca08031f642a844a85c7ca3d7b39df Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Fri, 13 Jul 2018 01:08:13 -0400
Subject: [PATCH 2/2] Annotate reason for Axes3D import in examples.

---
 examples/frontpage/3D.py                     | 4 +++-
 examples/mplot3d/2dcollections3d.py          | 4 +++-
 examples/mplot3d/3d_bars.py                  | 3 ++-
 examples/mplot3d/bars3d.py                   | 4 +++-
 examples/mplot3d/custom_shaded_3d_surface.py | 4 +++-
 examples/mplot3d/hist3d.py                   | 4 +++-
 examples/mplot3d/lines3d.py                  | 8 +++++---
 examples/mplot3d/lorenz_attractor.py         | 3 ++-
 examples/mplot3d/mixed_subplots.py           | 4 +++-
 examples/mplot3d/offset.py                   | 4 +++-
 examples/mplot3d/pathpatch3d.py              | 6 +++---
 examples/mplot3d/polys3d.py                  | 4 +++-
 examples/mplot3d/quiver3d.py                 | 4 +++-
 examples/mplot3d/scatter3d.py                | 4 +++-
 examples/mplot3d/subplot3d.py                | 5 ++++-
 examples/mplot3d/surface3d.py                | 4 +++-
 examples/mplot3d/surface3d_2.py              | 4 +++-
 examples/mplot3d/surface3d_3.py              | 4 +++-
 examples/mplot3d/surface3d_radial.py         | 4 +++-
 examples/mplot3d/text3d.py                   | 4 +++-
 examples/mplot3d/tricontour3d.py             | 4 +++-
 examples/mplot3d/tricontourf3d.py            | 4 +++-
 examples/mplot3d/trisurf3d.py                | 4 +++-
 examples/mplot3d/trisurf3d_2.py              | 4 +++-
 examples/mplot3d/voxels.py                   | 5 ++++-
 examples/mplot3d/voxels_numpy_logo.py        | 4 +++-
 examples/mplot3d/voxels_rgb.py               | 4 +++-
 examples/mplot3d/voxels_torus.py             | 4 +++-
 examples/mplot3d/wire3d_animation_sgskip.py  | 4 +++-
 examples/pyplots/whats_new_1_subplot3d.py    | 4 +++-
 30 files changed, 92 insertions(+), 34 deletions(-)

diff --git a/examples/frontpage/3D.py b/examples/frontpage/3D.py
index d08b52f54b24..ee93026ed06e 100644
--- a/examples/frontpage/3D.py
+++ b/examples/frontpage/3D.py
@@ -6,7 +6,9 @@
 This example reproduces the frontpage 3D example.
 
 """
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 from matplotlib import cbook
 from matplotlib import cm
 from matplotlib.colors import LightSource
diff --git a/examples/mplot3d/2dcollections3d.py b/examples/mplot3d/2dcollections3d.py
index 21a7a4148749..589e1083f7f5 100644
--- a/examples/mplot3d/2dcollections3d.py
+++ b/examples/mplot3d/2dcollections3d.py
@@ -7,7 +7,9 @@
 selective axes of a 3D plot.
 """
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import numpy as np
 import matplotlib.pyplot as plt
 
diff --git a/examples/mplot3d/3d_bars.py b/examples/mplot3d/3d_bars.py
index abacacc85dce..483dbcc4fb71 100644
--- a/examples/mplot3d/3d_bars.py
+++ b/examples/mplot3d/3d_bars.py
@@ -10,7 +10,8 @@
 
 import numpy as np
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
 
 
 # setup the figure and axes
diff --git a/examples/mplot3d/bars3d.py b/examples/mplot3d/bars3d.py
index 2cb2a5078b35..e30175ffac41 100644
--- a/examples/mplot3d/bars3d.py
+++ b/examples/mplot3d/bars3d.py
@@ -7,7 +7,9 @@
 planes y=0, y=1, etc.
 """
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/custom_shaded_3d_surface.py b/examples/mplot3d/custom_shaded_3d_surface.py
index 2c37bfae0fc9..366658856470 100644
--- a/examples/mplot3d/custom_shaded_3d_surface.py
+++ b/examples/mplot3d/custom_shaded_3d_surface.py
@@ -6,7 +6,9 @@
 Demonstrates using custom hillshading in a 3D surface plot.
 """
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 from matplotlib import cbook
 from matplotlib import cm
 from matplotlib.colors import LightSource
diff --git a/examples/mplot3d/hist3d.py b/examples/mplot3d/hist3d.py
index 9897f1606c5b..4cab341a64a2 100644
--- a/examples/mplot3d/hist3d.py
+++ b/examples/mplot3d/hist3d.py
@@ -6,7 +6,9 @@
 Demo of a histogram for 2 dimensional data as a bar graph in 3D.
 """
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/lines3d.py b/examples/mplot3d/lines3d.py
index 34ef9328c663..e0e45b1c051c 100644
--- a/examples/mplot3d/lines3d.py
+++ b/examples/mplot3d/lines3d.py
@@ -6,12 +6,14 @@
 This example demonstrates plotting a parametric curve in 3D.
 '''
 
-import matplotlib as mpl
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import numpy as np
 import matplotlib.pyplot as plt
 
-mpl.rcParams['legend.fontsize'] = 10
+
+plt.rcParams['legend.fontsize'] = 10
 
 fig = plt.figure()
 ax = fig.gca(projection='3d')
diff --git a/examples/mplot3d/lorenz_attractor.py b/examples/mplot3d/lorenz_attractor.py
index 47b21292b4cb..5a1328a769d3 100644
--- a/examples/mplot3d/lorenz_attractor.py
+++ b/examples/mplot3d/lorenz_attractor.py
@@ -15,7 +15,8 @@
 
 import numpy as np
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
 
 
 def lorenz(x, y, z, s=10, r=28, b=2.667):
diff --git a/examples/mplot3d/mixed_subplots.py b/examples/mplot3d/mixed_subplots.py
index fd1af313b6e3..0a13715aad1b 100644
--- a/examples/mplot3d/mixed_subplots.py
+++ b/examples/mplot3d/mixed_subplots.py
@@ -5,7 +5,9 @@
 
 This example shows a how to plot a 2D and 3D plot on the same figure.
 """
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/offset.py b/examples/mplot3d/offset.py
index da846c8cc26a..04c56ed2066e 100644
--- a/examples/mplot3d/offset.py
+++ b/examples/mplot3d/offset.py
@@ -13,7 +13,9 @@
 automatically trigger it.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/pathpatch3d.py b/examples/mplot3d/pathpatch3d.py
index 55d33dc94823..5976adf728a5 100644
--- a/examples/mplot3d/pathpatch3d.py
+++ b/examples/mplot3d/pathpatch3d.py
@@ -9,11 +9,11 @@
 import numpy as np
 import matplotlib.pyplot as plt
 from matplotlib.patches import Circle, PathPatch
-# register Axes3D class with matplotlib by importing Axes3D
-from mpl_toolkits.mplot3d import Axes3D
-import mpl_toolkits.mplot3d.art3d as art3d
 from matplotlib.text import TextPath
 from matplotlib.transforms import Affine2D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+import mpl_toolkits.mplot3d.art3d as art3d
 
 
 def text3d(ax, xyz, s, zdir="z", size=None, angle=0, usetex=False, **kwargs):
diff --git a/examples/mplot3d/polys3d.py b/examples/mplot3d/polys3d.py
index 09adab3db8ba..2f7769bb784c 100644
--- a/examples/mplot3d/polys3d.py
+++ b/examples/mplot3d/polys3d.py
@@ -8,7 +8,9 @@
 of 'jagged stained glass' effect.
 """
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 from matplotlib.collections import PolyCollection
 import matplotlib.pyplot as plt
 from matplotlib import colors as mcolors
diff --git a/examples/mplot3d/quiver3d.py b/examples/mplot3d/quiver3d.py
index 16ba7eab0190..6921b4a1d26c 100644
--- a/examples/mplot3d/quiver3d.py
+++ b/examples/mplot3d/quiver3d.py
@@ -6,7 +6,9 @@
 Demonstrates plotting directional arrows at points on a 3d meshgrid.
 '''
 
-from mpl_toolkits.mplot3d import axes3d
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/scatter3d.py b/examples/mplot3d/scatter3d.py
index 090ace56e1ed..d8c6a05606cd 100644
--- a/examples/mplot3d/scatter3d.py
+++ b/examples/mplot3d/scatter3d.py
@@ -6,7 +6,9 @@
 Demonstration of a basic scatterplot in 3D.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/subplot3d.py b/examples/mplot3d/subplot3d.py
index 9ece9f7ddc02..e9c1c3f2d712 100644
--- a/examples/mplot3d/subplot3d.py
+++ b/examples/mplot3d/subplot3d.py
@@ -7,10 +7,13 @@
 '''
 
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d.axes3d import Axes3D, get_test_data
 from matplotlib import cm
 import numpy as np
 
+from mpl_toolkits.mplot3d.axes3d import get_test_data
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 
 # set up a figure twice as wide as it is tall
 fig = plt.figure(figsize=plt.figaspect(0.5))
diff --git a/examples/mplot3d/surface3d.py b/examples/mplot3d/surface3d.py
index 44133c271c02..eac122b6aa13 100644
--- a/examples/mplot3d/surface3d.py
+++ b/examples/mplot3d/surface3d.py
@@ -10,7 +10,9 @@
 z axis tick labels.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 from matplotlib import cm
 from matplotlib.ticker import LinearLocator, FormatStrFormatter
diff --git a/examples/mplot3d/surface3d_2.py b/examples/mplot3d/surface3d_2.py
index bfc60ae563ac..fe3c2fe476ea 100644
--- a/examples/mplot3d/surface3d_2.py
+++ b/examples/mplot3d/surface3d_2.py
@@ -6,7 +6,9 @@
 Demonstrates a very basic plot of a 3D surface using a solid color.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/surface3d_3.py b/examples/mplot3d/surface3d_3.py
index bef4e41acf43..d75dc6680152 100644
--- a/examples/mplot3d/surface3d_3.py
+++ b/examples/mplot3d/surface3d_3.py
@@ -6,7 +6,9 @@
 Demonstrates plotting a 3D surface colored in a checkerboard pattern.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 from matplotlib.ticker import LinearLocator
 import numpy as np
diff --git a/examples/mplot3d/surface3d_radial.py b/examples/mplot3d/surface3d_radial.py
index 9125624eca45..521f6195330d 100644
--- a/examples/mplot3d/surface3d_radial.py
+++ b/examples/mplot3d/surface3d_radial.py
@@ -10,7 +10,9 @@
 Example contributed by Armin Moser.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/text3d.py b/examples/mplot3d/text3d.py
index d26cf2b74eaf..ed4934faf5a1 100644
--- a/examples/mplot3d/text3d.py
+++ b/examples/mplot3d/text3d.py
@@ -16,7 +16,9 @@
 
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 
 
diff --git a/examples/mplot3d/tricontour3d.py b/examples/mplot3d/tricontour3d.py
index 7e9e6971bb62..feb187cbaa16 100644
--- a/examples/mplot3d/tricontour3d.py
+++ b/examples/mplot3d/tricontour3d.py
@@ -9,8 +9,10 @@
 tricontourf3d_demo shows the filled version of this example.
 """
 
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.tri as tri
 import numpy as np
 
diff --git a/examples/mplot3d/tricontourf3d.py b/examples/mplot3d/tricontourf3d.py
index eebb3ef62e6a..d25b2dbd1ea5 100644
--- a/examples/mplot3d/tricontourf3d.py
+++ b/examples/mplot3d/tricontourf3d.py
@@ -9,8 +9,10 @@
 tricontour3d_demo shows the unfilled version of this example.
 """
 
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.tri as tri
 import numpy as np
 
diff --git a/examples/mplot3d/trisurf3d.py b/examples/mplot3d/trisurf3d.py
index 4d6283cad211..070a3154f2cb 100644
--- a/examples/mplot3d/trisurf3d.py
+++ b/examples/mplot3d/trisurf3d.py
@@ -6,7 +6,9 @@
 Plot a 3D surface with a triangular mesh.
 '''
 
-from mpl_toolkits.mplot3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 
diff --git a/examples/mplot3d/trisurf3d_2.py b/examples/mplot3d/trisurf3d_2.py
index 24d19e60b498..b948c1b14b5d 100644
--- a/examples/mplot3d/trisurf3d_2.py
+++ b/examples/mplot3d/trisurf3d_2.py
@@ -12,9 +12,11 @@
 
 import numpy as np
 import matplotlib.pyplot as plt
-from mpl_toolkits.mplot3d import Axes3D
 import matplotlib.tri as mtri
 
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 
 fig = plt.figure(figsize=plt.figaspect(0.5))
 
diff --git a/examples/mplot3d/voxels.py b/examples/mplot3d/voxels.py
index 76cf64c33a00..4ba96fff6c65 100644
--- a/examples/mplot3d/voxels.py
+++ b/examples/mplot3d/voxels.py
@@ -8,7 +8,10 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
-from mpl_toolkits.mplot3d import Axes3D
+
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 
 # prepare some coordinates
 x, y, z = np.indices((8, 8, 8))
diff --git a/examples/mplot3d/voxels_numpy_logo.py b/examples/mplot3d/voxels_numpy_logo.py
index 648a3cff7822..38b00b49f4de 100644
--- a/examples/mplot3d/voxels_numpy_logo.py
+++ b/examples/mplot3d/voxels_numpy_logo.py
@@ -7,7 +7,9 @@
 '''
 import matplotlib.pyplot as plt
 import numpy as np
-from mpl_toolkits.mplot3d import Axes3D
+
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
 
 
 def explode(data):
diff --git a/examples/mplot3d/voxels_rgb.py b/examples/mplot3d/voxels_rgb.py
index 1b577cad47fe..7b012b2a61f8 100644
--- a/examples/mplot3d/voxels_rgb.py
+++ b/examples/mplot3d/voxels_rgb.py
@@ -8,7 +8,9 @@
 
 import matplotlib.pyplot as plt
 import numpy as np
-from mpl_toolkits.mplot3d import Axes3D
+
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
 
 
 def midpoints(x):
diff --git a/examples/mplot3d/voxels_torus.py b/examples/mplot3d/voxels_torus.py
index 4f60e31403d8..3112f82792da 100644
--- a/examples/mplot3d/voxels_torus.py
+++ b/examples/mplot3d/voxels_torus.py
@@ -9,7 +9,9 @@
 import matplotlib.pyplot as plt
 import matplotlib.colors
 import numpy as np
-from mpl_toolkits.mplot3d import Axes3D
+
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
 
 
 def midpoints(x):
diff --git a/examples/mplot3d/wire3d_animation_sgskip.py b/examples/mplot3d/wire3d_animation_sgskip.py
index 303a2817a0df..4e727817264c 100644
--- a/examples/mplot3d/wire3d_animation_sgskip.py
+++ b/examples/mplot3d/wire3d_animation_sgskip.py
@@ -10,7 +10,9 @@
 """
 
 
-from mpl_toolkits.mplot3d import axes3d
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 import matplotlib.pyplot as plt
 import numpy as np
 import time
diff --git a/examples/pyplots/whats_new_1_subplot3d.py b/examples/pyplots/whats_new_1_subplot3d.py
index 0e69530deec4..96886b0e1f8c 100644
--- a/examples/pyplots/whats_new_1_subplot3d.py
+++ b/examples/pyplots/whats_new_1_subplot3d.py
@@ -5,7 +5,9 @@
 
 Create two three-dimensional plots in the same figure.
 """
-from mpl_toolkits.mplot3d.axes3d import Axes3D
+# This import registers the 3D projection, but is otherwise unused.
+from mpl_toolkits.mplot3d import Axes3D  # noqa: F401 unused import
+
 from matplotlib import cm
 #from matplotlib.ticker import LinearLocator, FixedLocator, FormatStrFormatter
 import matplotlib.pyplot as plt