@@ -91,7 +91,6 @@ class RedirectFrom(Directive):
     def run(self):
         redirected_doc, = self.arguments
         env = self.app.env
-        builder = self.app.builder
         domain = env.get_domain('redirect_from')
         current_doc = env.path2doc(self.state.document.current_source)
         redirected_reldoc, _ = env.relfn2path(redirected_doc, current_doc)
 
@@ -29,7 +29,6 @@ def on_move(event):
     if event.inaxes:
         # get the x and y pixel coords
         x, y = event.x, event.y
-        ax = event.inaxes  # the axes instance
         print('data coords %f %f, pixel coords %f %f'
                 % (event.xdata, event.ydata, x, y))
 
 
@@ -190,7 +190,7 @@ def __init__(self, ax):
                                   animated=False)
         self.canvas.mpl_connect('key_press_event', self.on_key_press)
 
-    def draw(self, event):
+    def draw(self):
         draw_artist = self.ax.draw_artist
         if self.background is None:
             self.background = self.canvas.copy_from_bbox(self.ax.bbox)
@@ -318,7 +318,7 @@ def start_anim(event):
 
     def local_draw():
         if animation.ax.get_renderer_cache():
-            animation.draw(None)
+            animation.draw()
     start_anim.timer.add_callback(local_draw)
     start_anim.timer.start()
     canvas.mpl_connect('draw_event', on_redraw)
 
@@ -33,7 +33,7 @@ def some_function(x):
     def __init__(self, *args, **kwargs):
         if args and kwargs:
             raise TypeError("Only positional or keyword args are allowed")
-        self.params = params = args or kwargs
+        self.params = args or kwargs
 
     def __call__(self, func):
         if func.__doc__:
 
@@ -507,13 +507,7 @@ def seq_id():
     return '%06d' % next(_layoutboxobjnum)
 
 
-def print_children(lb):
-    """Print the children of the layoutbox."""
-    for child in lb.children:
-        print_children(child)
-
-
-def plot_children(fig, lg=None, level=0, printit=False):
+def plot_children(fig, lg=None, level=0):
     """Simple plotting to show where boxes are."""
     import matplotlib.pyplot as plt
     import matplotlib.patches as mpatches
 
@@ -284,24 +284,22 @@ def add_tool(self, name, tool, *args, **kwargs):
 
             # If initially toggled
             if tool_obj.toggled:
-                self._handle_toggle(tool_obj, None, None, None)
+                self._handle_toggle(tool_obj, None, None)
         tool_obj.set_figure(self.figure)
 
         event = ToolEvent('tool_added_event', self, tool_obj)
         self._callbacks.process(event.name, event)
 
         return tool_obj
 
-    def _handle_toggle(self, tool, sender, canvasevent, data):
+    def _handle_toggle(self, tool, canvasevent, data):
         """
         Toggle tools, need to untoggle prior to using other Toggle tool.
         Called from trigger_tool.
 
         Parameters
         ----------
         tool : `.ToolBase`
-        sender : object
-            Object that wishes to trigger the tool.
         canvasevent : Event
             Original Canvas event or None.
         data : object
@@ -360,7 +358,7 @@ def trigger_tool(self, name, sender=None, canvasevent=None, data=None):
             sender = self
 
         if isinstance(tool, backend_tools.ToolToggleBase):
-            self._handle_toggle(tool, sender, canvasevent, data)
+            self._handle_toggle(tool, canvasevent, data)
 
         tool.trigger(sender, canvasevent, data)  # Actually trigger Tool.
 
 
@@ -356,7 +356,6 @@ def _read(self):
         while True:
             byte = self.file.read(1)[0]
             self._dtable[byte](self, byte)
-            name = self._dtable[byte].__name__
             if byte == 140:                         # end of page
                 return True
             if self.state is _dvistate.post_post:   # end of file
 
@@ -890,7 +890,7 @@ def set_stretch(self, stretch):
             return
         try:
             stretch = int(stretch)
-        except ValueError as err:
+        except ValueError:
             pass
         else:
             if 0 <= stretch <= 1000:
 
@@ -3822,8 +3822,6 @@ def test_errorbar_nan(fig_test, fig_ref):
     es = np.array([4, 5, np.nan, np.nan, 6])
     ax.errorbar(xs, ys, es)
     ax = fig_ref.add_subplot()
-    ys = np.array([1, 2, np.nan, np.nan, 3])
-    es = np.array([4, 5, np.nan, np.nan, 6])
     ax.errorbar([0, 1], [1, 2], [4, 5])
     ax.errorbar([4], [3], [6], fmt="C0")
 
@@ -7787,10 +7785,7 @@ def test_patch_bounds():  # PR 19078
 def test_warn_ignored_scatter_kwargs():
     with pytest.warns(UserWarning,
                       match=r"You passed a edgecolor/edgecolors"):
-
-        c = plt.scatter(
-            [0], [0], marker="+", s=500, facecolor="r", edgecolor="b"
-        )
+        plt.scatter([0], [0], marker="+", s=500, facecolor="r", edgecolor="b")
 
 
 def test_artist_sublists():
 
@@ -29,7 +29,6 @@
 
 @pytest.fixture
 def qt_core(request):
-    backend, = request.node.get_closest_marker('backend').args
     qt_compat = pytest.importorskip('matplotlib.backends.qt_compat')
     QtCore = qt_compat.QtCore