Remove some references to Py2.

anntzer · anntzer · commit 14a8c6e61f76 · 2019-12-05T16:13:27.000+01:00
The checks in `conf.py` and `matplotlib/__init__.py` are not useful
because the files are in fact not Py2-compatible (this has been the case
for `__init__.py` for a while...) due to f-strings/nonlocal, so someone
trying to run the file on Py2 will get a SyntaxError instead of the
error message.

In image.py the cast to int remains necessary even on Py3 because
round(np.float) returns a np.float, not a np.int.
diff --git a/doc/conf.py b/doc/conf.py
@@ -19,9 +19,6 @@
 
 from datetime import datetime
 
-if sys.version_info < (3, 0, 0):
-    print("You're using python 2.x, conf.py works with python3+ only.")
-    exit()
 # If your extensions are in another directory, add it here. If the directory
 # is relative to the documentation root, use os.path.abspath to make it
 # absolute, like shown here.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -97,22 +97,7 @@
 
 Occasionally the internal documentation (python docstrings) will refer
 to MATLAB&reg;, a registered trademark of The MathWorks, Inc.
-
 """
-# NOTE: This file must remain Python 2 compatible for the foreseeable future,
-# to ensure that we error out properly for existing editable installs.
-
-import sys
-if sys.version_info < (3, 5):  # noqa: E402
-    raise ImportError("""
-Matplotlib 3.0+ does not support Python 2.x, 3.0, 3.1, 3.2, 3.3, or 3.4.
-Beginning with Matplotlib 3.0, Python 3.5 and above is required.
-
-See Matplotlib `INSTALL.rst` file for more information:
-
-    https://github.com/matplotlib/matplotlib/blob/master/INSTALL.rst
-
-""")
 
 import atexit
 from collections import namedtuple
@@ -131,6 +116,7 @@
 import re
 import shutil
 import subprocess
+import sys
 import tempfile
 
 # cbook must import matplotlib only within function
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -1167,7 +1167,6 @@ def make_image(self, renderer, magnification=1.0, unsampled=False):
         l, b, r, t = self.axes.bbox.extents
         width = (round(r) + 0.5) - (round(l) - 0.5)
         height = (round(t) + 0.5) - (round(b) - 0.5)
-        # The extra cast-to-int is only needed for python2
         width = int(round(width * magnification))
         height = int(round(height * magnification))
         if self._rgbacache is None:
diff --git a/lib/matplotlib/tests/test_category.py b/lib/matplotlib/tests/test_category.py
@@ -6,9 +6,6 @@
 import matplotlib.pyplot as plt
 import matplotlib.category as cat
 
-# Python2/3 text handling
-_to_str = cat.StrCategoryFormatter._text
-
 
 class TestUnitData:
     test_cases = [('single', (["hello world"], [0])),
@@ -156,14 +153,14 @@ def test_StrCategoryFormatter(self, ax, ydata):
         unit = cat.UnitData(ydata)
         labels = cat.StrCategoryFormatter(unit._mapping)
         for i, d in enumerate(ydata):
-            assert labels(i, i) == _to_str(d)
+            assert labels(i, i) == d
 
     @pytest.mark.parametrize("ydata", cases, ids=ids)
     @pytest.mark.parametrize("plotter", PLOT_LIST, ids=PLOT_IDS)
     def test_StrCategoryFormatterPlot(self, ax, ydata, plotter):
         plotter(ax, range(len(ydata)), ydata)
         for i, d in enumerate(ydata):
-            assert ax.yaxis.major.formatter(i, i) == _to_str(d)
+            assert ax.yaxis.major.formatter(i, i) == d
         assert ax.yaxis.major.formatter(i+1, i+1) == ""
         assert ax.yaxis.major.formatter(0, None) == ""
 
@@ -172,7 +169,8 @@ def axis_test(axis, labels):
     ticks = list(range(len(labels)))
     np.testing.assert_array_equal(axis.get_majorticklocs(), ticks)
     graph_labels = [axis.major.formatter(i, i) for i in ticks]
-    assert graph_labels == [_to_str(l) for l in labels]
+    # _text also decodes bytes as utf-8.
+    assert graph_labels == [cat.StrCategoryFormatter._text(l) for l in labels]
     assert list(axis.units._mapping.keys()) == [l for l in labels]
     assert list(axis.units._mapping.values()) == ticks
 
