matplotlib
diff --git a/‎examples/images_contours_and_fields/image_annotated_heatmap.py
Copy file name to clipboardExpand all lines: examples/images_contours_and_fields/image_annotated_heatmap.py
+5-2Lines changed: 5 additions & 2 deletions b/‎examples/images_contours_and_fields/image_annotated_heatmap.py
Copy file name to clipboardExpand all lines: examples/images_contours_and_fields/image_annotated_heatmap.py
+5-2Lines changed: 5 additions & 2 deletions
diff --git a/‎examples/widgets/annotated_cursor.py
Copy file name to clipboardExpand all lines: examples/widgets/annotated_cursor.py
+3-1Lines changed: 3 additions & 1 deletion b/‎examples/widgets/annotated_cursor.py
Copy file name to clipboardExpand all lines: examples/widgets/annotated_cursor.py
+3-1Lines changed: 3 additions & 1 deletion
diff --git a/‎lib/matplotlib/backends/backend_svg.py
Copy file name to clipboardExpand all lines: lib/matplotlib/backends/backend_svg.py
+2-2Lines changed: 2 additions & 2 deletions b/‎lib/matplotlib/backends/backend_svg.py
Copy file name to clipboardExpand all lines: lib/matplotlib/backends/backend_svg.py
+2-2Lines changed: 2 additions & 2 deletions
@@ -97,7 +97,7 @@
 
 
 def heatmap(data, row_labels, col_labels, ax=None,
-            cbar_kw={}, cbarlabel="", **kwargs):
+            cbar_kw=None, cbarlabel="", **kwargs):
     """
     Create a heatmap from a numpy array and two lists of labels.
 
@@ -120,9 +120,12 @@ def heatmap(data, row_labels, col_labels, ax=None,
         All other arguments are forwarded to `imshow`.
     """
 
-    if not ax:
+    if ax is None:
         ax = plt.gca()
 
+    if cbar_kw is None:
+        cbar_kw = {}
+
     # Plot the heatmap
     im = ax.imshow(data, **kwargs)
 
 
@@ -76,7 +76,9 @@ class AnnotatedCursor(Cursor):
     """
 
     def __init__(self, line, numberformat="{0:.4g};{1:.4g}", offset=(5, 5),
-                 dataaxis='x', textprops={}, **cursorargs):
+                 dataaxis='x', textprops=None, **cursorargs):
+        if textprops is None:
+            textprops = {}
         # The line object, for which the coordinates are displayed
         self.line = line
         # The format string, on which .format() is called for creating the text
 
@@ -249,8 +249,8 @@ def flush(self):
         pass  # replaced by the constructor
 
 
-def generate_transform(transform_list=[]):
-    if len(transform_list):
+def generate_transform(transform_list=None):
+    if transform_list:
         output = StringIO()
         for type, value in transform_list:
             if (type == 'scale' and (value == (1,) or value == (1, 1))