Resolve conflicts with Unidata#2420

Reconcile changes in patheffects.py and test_patheffects.py after Unidata#2420.
Also remove Matplotlib<3.3.0 considerations and satisfy the lint robots.

src/metpy/plots/patheffects.py

@@ -1,4 +1,4 @@
-#  Copyright (c) 2020,2022 MetPy Developers.
+#  Copyright (c) 2020,2022,2023 MetPy Developers.
 #  Distributed under the terms of the BSD 3-Clause License.
 #  SPDX-License-Identifier: BSD-3-Clause
 """Add effects to matplotlib paths."""
@@ -9,8 +9,6 @@
 import matplotlib.path as mpath
 import matplotlib.patheffects as mpatheffects
 import matplotlib.transforms as mtransforms
-from matplotlib.path import Path
-from matplotlib.patheffects import AbstractPathEffect
 import numpy as np
 
 from ..package_tools import Exporter
@@ -138,7 +136,7 @@ def draw_path(self, renderer, gc, path, affine, rgbFace=None):  # noqa: N803
 
 
 @exporter.export
-class ScallopedStroke(AbstractPathEffect):
+class ScallopedStroke(mpatheffects.AbstractPathEffect):
     """A line-based PathEffect which draws a path with a scalloped style.
 
     The spacing, length, and side of the scallops can be controlled. This implementation is
@@ -175,19 +173,14 @@ def __init__(self, offset=(0, 0), spacing=10.0, side='left', length=1.15, **kwar
         self._length = length
         self._gc = kwargs
 
-    def draw_path(self, renderer, gc, tpath, affine, rgbFace):  # noqa: N803
+    def draw_path(self, renderer, gc, path, affine, rgbFace=None):  # noqa: N803
         """Draw the path with updated gc."""
         # Do not modify the input! Use copy instead.
         gc0 = renderer.new_gc()
         gc0.copy_properties(gc)
 
         gc0 = self._update_gc(gc0, self._gc)
-        try:
-            # For matplotlib >= 3.2
-            trans = affine + self._offset_transform(renderer)
-        except TypeError:
-            # For matplotlib < 3.2
-            trans = self._offset_transform(renderer, affine)
+        trans = affine + self._offset_transform(renderer)
 
         theta = -np.radians(self._angle)
         trans_matrix = np.array([[np.cos(theta), -np.sin(theta)],
@@ -198,7 +191,7 @@ def draw_path(self, renderer, gc, tpath, affine, rgbFace):  # noqa: N803
 
         # Transform before evaluation because to_polygons works at resolution
         # of one -- assuming it is working in pixel space.
-        transpath = affine.transform_path(tpath)
+        transpath = affine.transform_path(path)
 
         # Evaluate path to straight line segments that can be used to
         # construct line scallops.
@@ -277,12 +270,12 @@ def draw_path(self, renderer, gc, tpath, affine, rgbFace):  # noqa: N803
                 i += 2
 
             # Build up vector of Path codes
-            codes = np.tile([Path.LINETO, Path.CURVE4,
-                             Path.CURVE4, Path.CURVE4], nverts)
-            codes[0] = Path.MOVETO
+            codes = np.tile([mpath.Path.LINETO, mpath.Path.CURVE4,
+                             mpath.Path.CURVE4, mpath.Path.CURVE4], nverts)
+            codes[0] = mpath.Path.MOVETO
 
             # Construct and draw resulting path
-            h = Path(verts, codes)
+            h = mpath.Path(verts, codes)
 
             # Transform back to data space during render
             renderer.draw_path(gc0, h, affine.inverted() + trans, rgbFace)

tests/plots/test_patheffects.py

@@ -1,17 +1,15 @@
-# Copyright (c) 2022 MetPy Developers.
+# Copyright (c) 2022,2023 MetPy Developers.
 # Distributed under the terms of the BSD 3-Clause License.
 # SPDX-License-Identifier: BSD-3-Clause
 """Test the `patheffects` module."""
+import matplotlib.patches as mpatches
+import matplotlib.path as mpath
 import matplotlib.pyplot as plt
 import numpy as np
 import pytest
 from scipy.interpolate import interp1d
 
-from metpy.plots import ColdFront, OccludedFront, StationaryFront, WarmFront
-import matplotlib.patches as patches
-from matplotlib.path import Path
-from metpy.plots import patheffects
-
+from metpy.plots import ColdFront, OccludedFront, ScallopedStroke, StationaryFront, WarmFront
 
 
 @pytest.mark.mpl_image_compare(remove_text=True, tolerance=0.)
@@ -74,15 +72,14 @@ def test_scalloped_stroke_closed():
     y = [1.264, 0.784, -0.076, -0.846, -1.126,
          -1.246, -1.006, 0.234, 0.754, 1.264]
     verts = np.array([[x, y] for x, y in zip(x, y)])
-    codes = np.repeat(Path.LINETO, len(x))
-    codes[0] = Path.MOVETO
-    codes[-1] = Path.CLOSEPOLY
+    codes = np.repeat(mpath.Path.LINETO, len(x))
+    codes[0] = mpath.Path.MOVETO
+    codes[-1] = mpath.Path.CLOSEPOLY
 
-    path = Path(verts, codes)
-    patch = patches.PathPatch(path, facecolor='#d10000', edgecolor='#000000',
-                              path_effects=[patheffects.ScallopedStroke(side='left',
-                                                                        spacing=10,
-                                                                        length=1.15)])
+    path = mpath.Path(verts, codes)
+    patch = mpatches.PathPatch(path, facecolor='#d10000', edgecolor='#000000',
+                               path_effects=[
+                                   ScallopedStroke(side='left', spacing=10, length=1.15)])
 
     ax.add_patch(patch)
     ax.axis('equal')
@@ -102,14 +99,13 @@ def test_scalloped_stroke_segment():
     x = np.arange(9)
     y = np.concatenate([np.arange(5), np.arange(3, -1, -1)])
     verts = np.array([[x, y] for x, y in zip(x, y)])
-    codes = np.repeat(Path.LINETO, len(x))
-    codes[0] = Path.MOVETO
-
-    path = Path(verts, codes)
-    patch = patches.PathPatch(path, facecolor='none', edgecolor='#000000',
-                              path_effects=[patheffects.ScallopedStroke(side='left',
-                                                                        spacing=10,
-                                                                        length=1.15)])
+    codes = np.repeat(mpath.Path.LINETO, len(x))
+    codes[0] = mpath.Path.MOVETO
+
+    path = mpath.Path(verts, codes)
+    patch = mpatches.PathPatch(path, facecolor='none', edgecolor='#000000',
+                               path_effects=[
+                                   ScallopedStroke(side='left', spacing=10, length=1.15)])
 
     ax.add_patch(patch)
     ax.axis('equal')