matplotlib · jklymak · Feb 7, 2019 · Feb 6, 2019
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -132,7 +132,6 @@
 import subprocess
 import tempfile
 import urllib.request
-import warnings
 
 # cbook must import matplotlib only within function
 # definitions, so it is safe to import from it here.
@@ -760,8 +759,7 @@ def __str__(self):
 
     def __iter__(self):
         """Yield sorted list of keys."""
-        with warnings.catch_warnings():
-            warnings.simplefilter('ignore', MatplotlibDeprecationWarning)
+        with cbook._suppress_matplotlib_deprecation_warning():
             yield from sorted(dict.__iter__(self))
 
     def __len__(self):
@@ -917,8 +915,7 @@ def rc_params_from_file(fname, fail_on_error=False, use_default_template=True):
         return config_from_file
 
     iter_params = defaultParams.items()
-    with warnings.catch_warnings():
-        warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+    with cbook._suppress_matplotlib_deprecation_warning():
         config = RcParams([(key, default) for key, (default, _) in iter_params
                            if key not in _all_deprecated])
     config.update(config_from_file)
@@ -958,8 +955,7 @@ def rc_params_from_file(fname, fail_on_error=False, use_default_template=True):
         rcParams['examples.directory'] = _fullpath
 
 
-with warnings.catch_warnings():
-    warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+with cbook._suppress_matplotlib_deprecation_warning():
     rcParamsOrig = RcParams(rcParams.copy())
     rcParamsDefault = RcParams([(key, default) for key, (default, converter) in
                                 defaultParams.items()
@@ -1062,8 +1058,7 @@ def rcdefaults():
     """
     # Deprecation warnings were already handled when creating rcParamsDefault,
     # no need to reemit them here.
-    with warnings.catch_warnings():
-        warnings.simplefilter("ignore", mplDeprecation)
+    with cbook._suppress_matplotlib_deprecation_warning():
         from .style.core import STYLE_BLACKLIST
         rcParams.clear()
         rcParams.update({k: v for k, v in rcParamsDefault.items()
@@ -1079,8 +1074,7 @@ def rc_file_defaults():
     """
     # Deprecation warnings were already handled when creating rcParamsOrig, no
     # need to reemit them here.
-    with warnings.catch_warnings():
-        warnings.simplefilter("ignore", mplDeprecation)
+    with cbook._suppress_matplotlib_deprecation_warning():
         from .style.core import STYLE_BLACKLIST
         rcParams.update({k: rcParamsOrig[k] for k in rcParamsOrig
                          if k not in STYLE_BLACKLIST})
@@ -1106,8 +1100,7 @@ def rc_file(fname, *, use_default_template=True):
     """
     # Deprecation warnings were already handled in rc_params_from_file, no need
     # to reemit them here.
-    with warnings.catch_warnings():
-        warnings.simplefilter("ignore", mplDeprecation)
+    with cbook._suppress_matplotlib_deprecation_warning():
         from .style.core import STYLE_BLACKLIST
         rc_from_file = rc_params_from_file(
             fname, use_default_template=use_default_template)

diff --git a/lib/matplotlib/cbook/__init__.py b/lib/matplotlib/cbook/__init__.py
@@ -33,6 +33,7 @@
 import matplotlib
 from .deprecation import (
     deprecated, warn_deprecated, _rename_parameter,
+    _suppress_matplotlib_deprecation_warning,
     MatplotlibDeprecationWarning, mplDeprecation)
 
 

diff --git a/lib/matplotlib/cbook/deprecation.py b/lib/matplotlib/cbook/deprecation.py
@@ -1,5 +1,7 @@
+import contextlib
 import functools
 import inspect
+import warnings
 
 
 class MatplotlibDeprecationWarning(UserWarning):
@@ -306,3 +308,10 @@ def wrapper(*args, **kwargs):
     # pyplot would explicitly pass both arguments to the Axes method.
 
     return wrapper
+
+
+@contextlib.contextmanager
+def _suppress_matplotlib_deprecation_warning():
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+        yield
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -25,7 +25,6 @@
 import re
 import sys
 import time
-import warnings
 
 from cycler import cycler
 import matplotlib
@@ -2262,9 +2261,7 @@ def plotfile(fname, cols=(0,), plotfuncs=None,
 
     if plotfuncs is None:
         plotfuncs = {}
-    from matplotlib.cbook import MatplotlibDeprecationWarning
-    with warnings.catch_warnings():
-        warnings.simplefilter('ignore', MatplotlibDeprecationWarning)
+    with cbook._suppress_matplotlib_deprecation_warning():
         r = mlab._csv2rec(fname, comments=comments, skiprows=skiprows,
                           checkrows=checkrows, delimiter=delimiter,
                           names=names)

diff --git a/lib/matplotlib/style/core.py b/lib/matplotlib/style/core.py
@@ -19,7 +19,6 @@
 
 import matplotlib as mpl
 from matplotlib import cbook, rc_params_from_file, rcParamsDefault
-from matplotlib.cbook import MatplotlibDeprecationWarning
 
 _log = logging.getLogger(__name__)
 
@@ -103,8 +102,7 @@ def use(style):
         elif style == 'default':
             # Deprecation warnings were already handled when creating
             # rcParamsDefault, no need to reemit them here.
-            with warnings.catch_warnings():
-                warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+            with cbook._suppress_matplotlib_deprecation_warning():
                 _apply_style(rcParamsDefault, warn=False)
         elif style in library:
             _apply_style(library[style])

diff --git a/lib/matplotlib/testing/__init__.py b/lib/matplotlib/testing/__init__.py
@@ -6,7 +6,7 @@
 import warnings
 
 import matplotlib as mpl
-from matplotlib.cbook import MatplotlibDeprecationWarning
+from matplotlib import cbook
 
 _log = logging.g
1E0A
etLogger(__name__)
 
@@ -42,8 +42,7 @@ def setup():
 
     mpl.use('Agg', force=True, warn=False)  # use Agg backend for these tests
 
-    with warnings.catch_warnings():
-        warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+    with cbook._suppress_matplotlib_deprecation_warning():
         mpl.rcdefaults()  # Start with all defaults
 
     # These settings *must* be hardcoded for running the comparison tests and

diff --git a/lib/matplotlib/testing/conftest.py b/lib/matplotlib/testing/conftest.py
@@ -1,10 +1,7 @@
-import warnings
-
 import pytest
 
 import matplotlib
 from matplotlib import cbook
-from matplotlib.cbook import MatplotlibDeprecationWarning
 
 
 def pytest_configure(config):
@@ -53,8 +50,7 @@ def mpl_test_settings(request):
                                 .format(backend, exc))
                 else:
                     raise
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", MatplotlibDeprecationWarning)
+        with cbook._suppress_matplotlib_deprecation_warning():
             matplotlib.style.use(style)
         try:
             yield

diff --git a/lib/matplotlib/tests/test_axes.py b/lib/matplotlib/tests/test_axes.py
@@ -5608,14 +5608,12 @@ def test_none_kwargs():
 
 
 def test_ls_ds_conflict():
-    with warnings.catch_warnings():
-        # Passing the drawstyle with the linestyle is deprecated since 3.1.
-        # We still need to test this until it's removed from the code.
-        # But we don't want to see the deprecation warning in the test.
-        warnings.filterwarnings('ignore',
-                                category=MatplotlibDeprecationWarning)
-        with pytest.raises(ValueError):
-            plt.plot(range(32), linestyle='steps-pre:', drawstyle='steps-post')
+    # Passing the drawstyle with the linestyle is deprecated since 3.1.
+    # We still need to test this until it's removed from the code.
+    # But we don't want to see the deprecation warning in the test.
+    with matplotlib.cbook._suppress_matplotlib_deprecation_warning(), \
+         pytest.raises(ValueError):
+        plt.plot(range(32), linestyle='steps-pre:', drawstyle='steps-post')
 
 
 def test_bar_uint8():