Remove many unused variables.

They can be detected by removing the exclusion of F841 in .flake8.

Some other unused variables have been left in, either for symmetry in
the code or because their lack of use may possibly indicate a bug that
needs to be investigated.

Author: anntzer

doc/sphinxext/github.py

@@ -103,7 +103,6 @@ def ghuser_role(name, rawtext, text, lineno, inliner, options={}, content=[]):
     :param options: Directive options for customization.
     :param content: The directive content for customization.
     """
-    app = inliner.document.settings.env.app
     ref = 'https://www.github.com/' + text
     node = nodes.reference(rawtext, text, refuri=ref, **options)
     return [node], []

examples/axes_grid1/demo_axes_grid.py

@@ -28,13 +28,10 @@ def demo_simple_grid(fig):
                      axes_pad=0.05,
                      label_mode="1",
                      )
-
     Z, extent = get_demo_image()
     for ax in grid:
-        im = ax.imshow(Z, extent=extent, interpolation="nearest")
-
-    # This only affects axes in first column and second row as share_all =
-    # False.
+        ax.imshow(Z, extent=extent, interpolation="nearest")
+    # This only affects axes in first column and second row as share_all=False.
     grid.axes_llc.set_xticks([-2, 0, 2])
     grid.axes_llc.set_yticks([-2, 0, 2])
 

examples/axes_grid1/demo_edge_colorbar.py

@@ -41,7 +41,7 @@ def demo_bottom_cbar(fig):
         im = grid[i].imshow(Z, extent=extent, interpolation="nearest",
                             cmap=cmaps[i//2])
         if i % 2:
-            cbar = grid.cbar_axes[i//2].colorbar(im)
+            grid.cbar_axes[i//2].colorbar(im)
 
     for cax in grid.cbar_axes:
         cax.toggle_label(True)

examples/event_handling/pick_event_demo.py

@@ -83,7 +83,7 @@ def pick_simple():
     line, = ax1.plot(rand(100), 'o', picker=5)  # 5 points tolerance
 
     # pick the rectangle
-    bars = ax2.bar(range(10), rand(10), picker=True)
+    ax2.bar(range(10), rand(10), picker=True)
     for label in ax2.get_xticklabels():  # make the xtick labels pickable
         label.set_picker(True)
 
@@ -157,18 +157,17 @@ def onpick3(event):
         print('onpick3 scatter:', ind, x[ind], y[ind])
 
     fig, ax = plt.subplots()
-    col = ax.scatter(x, y, 100*s, c, picker=True)
-    #fig.savefig('pscoll.eps')
+    ax.scatter(x, y, 100*s, c, picker=True)
     fig.canvas.mpl_connect('pick_event', onpick3)
 
 
 def pick_image():
     # picking images (matplotlib.image.AxesImage)
     fig, ax = plt.subplots()
-    im1 = ax.imshow(rand(10, 5), extent=(1, 2, 1, 2), picker=True)
-    im2 = ax.imshow(rand(5, 10), extent=(3, 4, 1, 2), picker=True)
-    im3 = ax.imshow(rand(20, 25), extent=(1, 2, 3, 4), picker=True)
-    im4 = ax.imshow(rand(30, 12), extent=(3, 4, 3, 4), picker=True)
+    ax.imshow(rand(10, 5), extent=(1, 2, 1, 2), picker=True)
+    ax.imshow(rand(5, 10), extent=(3, 4, 1, 2), picker=True)
+    ax.imshow(rand(20, 25), extent=(1, 2, 3, 4), picker=True)
+    ax.imshow(rand(30, 12), extent=(3, 4, 3, 4), picker=True)
     ax.axis([0, 5, 0, 5])
 
     def onpick4(event):

examples/misc/demo_agg_filter.py

@@ -187,8 +187,8 @@ def filtered_text(ax):
     Z = (Z1 - Z2) * 2
 
     # draw
-    im = ax.imshow(Z, interpolation='bilinear', origin='lower',
-                   cmap=cm.gray, extent=(-3, 3, -2, 2))
+    ax.imshow(Z, interpolation='bilinear', origin='lower',
+              cmap=cm.gray, extent=(-3, 3, -2, 2))
     levels = np.arange(-1.2, 1.6, 0.2)
     CS = ax.contour(Z, levels,
                     origin='lower',

examples/units/basic_units.py

@@ -25,9 +25,7 @@ def __get__(self, obj, objtype=None):
 class TaggedValueMeta(type):
     def __init__(self, name, bases, dict):
         for fn_name in self._proxies:
-            try:
-                dummy = getattr(self, fn_name)
-            except AttributeError:
+            if not hasattr(self, fn_name):
                 setattr(self, fn_name,
                         ProxyDelegate(fn_name, self._proxies[fn_name]))
 

examples/widgets/menu.py

@@ -132,8 +132,6 @@ def __init__(self, fig, menuitems):
         maxw = max(item.labelwidth for item in menuitems)
         maxh = max(item.labelheight for item in menuitems)
 
-        totalh = self.numitems*maxh + (self.numitems + 1)*2*MenuItem.pady
-
         x0 = 100
         y0 = 400
 

lib/matplotlib/axes/_secondary_axes.py

@@ -295,16 +295,14 @@ def _set_lims(self):
         if self._orientation == 'x':
             lims = self._parent.get_xlim()
             set_lim = self.set_xlim
-            trans = self.xaxis.get_transform()
         if self._orientation == 'y':
             lims = self._parent.get_ylim()
             set_lim = self.set_ylim
-            trans = self.yaxis.get_transform()
         order = lims[0] < lims[1]
         lims = self._functions[0](np.array(lims))
         neworder = lims[0] < lims[1]
         if neworder != order:
-            # flip because the transform will take care of the flipping..
+            # Flip because the transform will take care of the flipping.
             lims = lims[::-1]
         set_lim(lims)
 

lib/matplotlib/backends/backend_gtk3.py

@@ -235,7 +235,7 @@ def motion_notify_event(self, widget, event):
         if event.is_hint:
             t, x, y, state = event.window.get_pointer()
         else:
-            x, y, state = event.x, event.y, event.get_state()
+            x, y = event.x, event.y
 
         # flipy so y=0 is bottom of canvas
         y = self.get_allocation().height - y
@@ -582,7 +582,8 @@ def configure_subplots(self, button):
         toolfig = Figure(figsize=(6, 3))
         canvas = self._get_canvas(toolfig)
         toolfig.subplots_adjust(top=0.9)
-        tool = SubplotTool(self.canvas.figure, toolfig)
+        # Need to keep a reference to the tool.
+        _tool = SubplotTool(self.canvas.figure, toolfig)
 
         w = int(toolfig.bbox.width)
         h = int(toolfig.bbox.height)

lib/matplotlib/backends/backend_gtk3agg.py

@@ -61,9 +61,8 @@ def blit(self, bbox=None):
             bbox = self.figure.bbox
 
         allocation = self.get_allocation()
-        w, h = allocation.width, allocation.height
         x = int(bbox.x0)
-        y = h - int(bbox.y1)
+        y = allocation.height - int(bbox.y1)
         width = int(bbox.x1) - int(bbox.x0)
         height = int(bbox.y1) - int(bbox.y0)