Fix #5777. Don't warn when applying default style

lib/matplotlib/style/core.py

@@ -43,13 +43,14 @@
     'savefig.directory', 'tk.window_focus', 'hardcopy.docstring'])
 
 
-def _remove_blacklisted_style_params(d):
+def _remove_blacklisted_style_params(d, warn=True):
     o = {}
     for key, val in d.items():
         if key in STYLE_BLACKLIST:
-            warnings.warn(
-                "Style includes a parameter, '{0}', that is not related to "
-                "style.  Ignoring".format(key))
+            if warn:
+                warnings.warn(
+                    "Style includes a parameter, '{0}', that is not related "
+                    "to style.  Ignoring".format(key))
         else:
             o[key] = val
     return o
@@ -60,8 +61,8 @@ def is_style_file(filename):
     return STYLE_FILE_PATTERN.match(filename) is not None
 
 
-def _apply_style(d):
-    mpl.rcParams.update(_remove_blacklisted_style_params(d))
+def _apply_style(d, warn=True):
+    mpl.rcParams.update(_remove_blacklisted_style_params(d, warn=warn))
 
 
 def use(style):
@@ -98,7 +99,7 @@ def use(style):
         if not cbook.is_string_like(style):
             _apply_style(style)
         elif style == 'default':
-            _apply_style(rcParamsDefault)
+            _apply_style(rcParamsDefault, warn=False)
         elif style in library:
             _apply_style(library[style])
         else:

lib/matplotlib/tests/test_backend_qt4.py

@@ -7,7 +7,7 @@
 from matplotlib.testing.decorators import cleanup, switch_backend
 from matplotlib.testing.decorators import knownfailureif
 from matplotlib._pylab_helpers import Gcf
-import matplotlib.style as mstyle
+import matplotlib
 import copy
 
 try:
@@ -17,7 +17,7 @@
     import mock
 
 try:
-    with mstyle.context({'backend': 'Qt4Agg'}):
+    with matplotlib.rc_context(rc={'backend': 'Qt4Agg'}):
         from matplotlib.backends.qt_compat import QtCore
 
     from matplotlib.backends.backend_qt4 import (MODIFIER_KEYS,

lib/matplotlib/tests/test_backend_qt5.py

@@ -6,7 +6,7 @@
 from matplotlib.testing.decorators import cleanup, switch_backend
 from matplotlib.testing.decorators import knownfailureif
 from matplotlib._pylab_helpers import Gcf
-import matplotlib.style as mstyle
+import matplotlib
 import copy
 
 try:
@@ -16,7 +16,7 @@
     import mock
 
 try:
-    with mstyle.context({'backend': 'Qt5Agg'}):
+    with matplotlib.rc_context(rc={'backend': 'Qt5Agg'}):
         from matplotlib.backends.qt_compat import QtCore, __version__
     from matplotlib.backends.backend_qt5 import (MODIFIER_KEYS,
                                                  SUPER, ALT, CTRL, SHIFT)