Remove mutable defaults from tool manager functions

QuLogic · QuLogic · commit cc62eba10d39 · 2026-01-23T19:15:49.000-05:00
This is generally frowned upon (though we don't actually change it, so
it's safe), but more importantly, Sphinx tries to put all the values
into the docstring, which just looks bad.
diff --git a/lib/matplotlib/backend_tools.py b/lib/matplotlib/backend_tools.py
@@ -934,6 +934,7 @@ def trigger(self, *args, **kwargs):
         self.toolmanager.message_event(message, self)
 
 
+#: The default tools to add to a tool manager.
 default_tools = {'home': ToolHome, 'back': ToolBack, 'forward': ToolForward,
                  'zoom': ToolZoom, 'pan': ToolPan,
                  'subplots': ConfigureSubplotsBase,
@@ -953,12 +954,13 @@ def trigger(self, *args, **kwargs):
                  'copy': ToolCopyToClipboardBase,
                  }
 
+#: The default tools to add to a container.
 default_toolbar_tools = [['navigation', ['home', 'back', 'forward']],
                          ['zoompan', ['pan', 'zoom', 'subplots']],
                          ['io', ['save', 'help']]]
 
 
-def add_tools_to_manager(toolmanager, tools=default_tools):
+def add_tools_to_manager(toolmanager, tools=None):
     """
     Add multiple tools to a `.ToolManager`.
 
@@ -968,14 +970,16 @@ def add_tools_to_manager(toolmanager, tools=default_tools):
         Manager to which the tools are added.
     tools : {str: class_like}, optional
         The tools to add in a {name: tool} dict, see
-        `.backend_managers.ToolManager.add_tool` for more info.
+        `.backend_managers.ToolManager.add_tool` for more info. If not specified, then
+        defaults to `.default_tools`.
     """
-
+    if tools is None:
+        tools = default_tools
     for name, tool in tools.items():
         toolmanager.add_tool(name, tool)
 
 
-def add_tools_to_container(container, tools=default_toolbar_tools):
+def add_tools_to_container(container, tools=None):
     """
     Add multiple tools to the container.
 
@@ -987,9 +991,11 @@ def add_tools_to_container(container, tools=default_toolbar_tools):
     tools : list, optional
         List in the form ``[[group1, [tool1, tool2 ...]], [group2, [...]]]``
         where the tools ``[tool1, tool2, ...]`` will display in group1.
-        See `.backend_bases.ToolContainerBase.add_tool` for details.
+        See `.backend_bases.ToolContainerBase.add_tool` for details. If not specified,
+        then defaults to `.default_toolbar_tools`.
     """
-
+    if tools is None:
+        tools = default_toolbar_tools
     for group, grouptools in tools:
         for position, tool in enumerate(grouptools):
             container.add_tool(tool, group, position)
