Merge pull request matplotlib#11166 from souravsingh/fix-warnings

MNT: Set stacklevel to 2 for backend_wx

Author: tacaswell

lib/matplotlib/backends/backend_wx.py

@@ -1555,7 +1555,7 @@ def save_figure(self, *args):
                 warnings.warn(
                     'extension %s did not match the selected '
                     'image type %s; going with %s' %
-                    (ext, format, ext), stacklevel=0)
+                    (ext, format, ext), stacklevel=2)
                 format = ext
             try:
                 self.canvas.figure.savefig(
@@ -1721,7 +1721,7 @@ def trigger(self, *args):
             warnings.warn(
                 'extension %s did not match the selected '
                 'image type %s; going with %s' %
-                (ext, format, ext), stacklevel=0)
+                (ext, format, ext), stacklevel=2)
             format = ext
         if default_dir != "":
             matplotlib.rcParams['savefig.directory'] = dirname