matplotlib
diff --git a/‎lib/matplotlib/backends/backend_pdf.py
Lines changed: 3 additions & 4 deletions b/‎lib/matplotlib/backends/backend_pdf.py
Lines changed: 3 additions & 4 deletions
diff --git a/‎lib/matplotlib/contour.py
Lines changed: 1 addition & 4 deletions b/‎lib/matplotlib/contour.py
Lines changed: 1 addition & 4 deletions
diff --git a/‎lib/matplotlib/figure.py b/‎lib/matplotlib/figure.py
@@ -1709,10 +1709,9 @@ def _writeImg(self, data, id, smask=None):
                 if bit_depth is None or palette is None:
                     raise RuntimeError("invalid PNG header")
                 palette = palette[:num_colors * 3]  # Trim padding
-                palette = pdfRepr(palette)
-                obj['ColorSpace'] = Verbatim(b'[/Indexed /DeviceRGB '
-                                             + str(num_colors - 1).encode()
-                                             + b' ' + palette + b']')
+                obj['ColorSpace'] = Verbatim(
+                    b'[/Indexed /DeviceRGB %d %s]'
+                    % (num_colors - 1, pdfRepr(palette)))
                 obj['BitsPerComponent'] = bit_depth
                 color_channels = 1
             else:
 
@@ -928,10 +928,7 @@ def __init__(self, ax, *args,
             )
 
     def get_transform(self):
-        """
-        Return the :class:`~matplotlib.transforms.Transform`
-        instance used by this ContourSet.
-        """
+        """Return the `.Transform` instance used by this ContourSet."""
         if self._transform is None:
             self._transform = self.axes.transData
         elif (not isinstance(self._transform, mtransforms.Transform)
 
@@ -1009,7 +1009,7 @@ def legend(self, *args, **kwargs):
         To make a legend for all artists on all Axes, call this function with
         an iterable of strings, one for each legend item. For example::
 
-            fig, (ax1, ax2)  = plt.subplots(1, 2)
+            fig, (ax1, ax2) = plt.subplots(1, 2)
             ax1.plot([1, 3, 5], color='blue')
             ax2.plot([2, 4, 6], color='red')
             fig.legend(['the blues', 'the reds'])
 
@@ -271,7 +271,7 @@ def _stride_windows(x, n, noverlap=0, axis=0):
         if axis == 0:
             return x[np.newaxis]
         else:
-            return x[np.newaxis].transpose()
+            return x[np.newaxis].T
     if n > x.size:
         raise ValueError('n cannot be greater than the length of x')
 
 
@@ -2424,8 +2424,7 @@ def transform_non_affine(self, points):
         elif not self._a.is_affine and self._b.is_affine:
             return self._a.transform_non_affine(points)
         else:
-            return self._b.transform_non_affine(
-                                self._a.transform(points))
+            return self._b.transform_non_affine(self._a.transform(points))
 
     def transform_path_non_affine(self, path):
         # docstring inherited
 
@@ -6
D7AE
09,10 +609,7 @@ def draw(self, renderer):
         if self._grid_helper is not None:
             self._grid_helper.update_lim(self.axes)
             gl = self._grid_helper.get_gridlines(self._which, self._axis)
-            if gl:
-                self.set_segments([np.transpose(l) for l in gl])
-            else:
-                self.set_segments([])
+            self.set_segments([np.transpose(l) for l in gl])
         super().draw(renderer)
 
 
 
@@ -293,7 +293,6 @@ def get_boundary(self):
         Return (N, 2) array of (x, y) coordinate of the boundary.
         """
         x0, x1, y0, y1 = self._extremes
-        tr = self._aux_trans
 
         xx = np.linspace(x0, x1, 100)
         yy0 = np.full_like(xx, y0)
@@ -304,9 +303,8 @@ def get_boundary(self):
 
         xxx = np.concatenate([xx[:-1], xx1[:-1], xx[-1:0:-1], xx0])
         yyy = np.concatenate([yy0[:-1], yy[:-1], yy1[:-1], yy[::-1]])
-        t = tr.transform(np.array([xxx, yyy]).transpose())
 
-        return t
+        return self._aux_trans.transform(np.column_stack([xxx, yyy]))
 
 
 class FloatingAxesBase: