Use itertools.pairwise instead of zip

This was added in 3.10.

Author: QuLogic

galleries/examples/units/basic_units.py

@@ -7,6 +7,7 @@
 
 """
 
+import itertools
 import math
 
 from packaging.version import parse as parse_version
@@ -254,7 +255,7 @@ def get_unit(self):
 
 class UnitResolver:
     def addition_rule(self, units):
-        for unit_1, unit_2 in zip(units[:-1], units[1:]):
+        for unit_1, unit_2 in itertools.pairwise(units):
             if unit_1 != unit_2:
                 return NotImplemented
         return units[0]

lib/matplotlib/tests/test_cbook.py

@@ -799,8 +799,8 @@ def check(x, rstride, cstride):
         row_inds = [*range(0, rows-1, rstride), rows-1]
         col_inds = [*range(0, cols-1, cstride), cols-1]
         polys = []
-        for rs, rs_next in zip(row_inds[:-1], row_inds[1:]):
-            for cs, cs_next in zip(col_inds[:-1], col_inds[1:]):
+        for rs, rs_next in itertools.pairwise(row_inds):
+            for cs, cs_next in itertools.pairwise(col_inds):
                 # +1 ensures we share edges between polygons
                 ps = cbook._array_perimeter(x[rs:rs_next+1, cs:cs_next+1]).T
                 polys.append(ps)

lib/matplotlib/transforms.py

@@ -38,6 +38,7 @@
 
 import copy
 import functools
+import itertools
 import textwrap
 import weakref
 import math
@@ -553,7 +554,7 @@ def splitx(self, *args):
         x0, y0, x1, y1 = self.extents
         w = x1 - x0
         return [Bbox([[x0 + xf0 * w, y0], [x0 + xf1 * w, y1]])
-                for xf0, xf1 in zip(xf[:-1], xf[1:])]
+                for xf0, xf1 in itertools.pairwise(xf)]
 
     def splity(self, *args):
         """
@@ -564,7 +565,7 @@ def splity(self, *args):
         x0, y0, x1, y1 = self.extents
         h = y1 - y0
         return [Bbox([[x0, y0 + yf0 * h], [x1, y0 + yf1 * h]])
-                for yf0, yf1 in zip(yf[:-1], yf[1:])]
+                for yf0, yf1 in itertools.pairwise(yf)]
 
     def count_contains(self, vertices):
         """

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -2206,8 +2206,8 @@ def plot_surface(self, X, Y, Z, *, norm=None, vmin=None,
             col_inds = list(range(0, cols-1, cstride)) + [cols-1]
 
             polys = []
-            for rs, rs_next in zip(row_inds[:-1], row_inds[1:]):
-                for cs, cs_next in zip(col_inds[:-1], col_inds[1:]):
+            for rs, rs_next in itertools.pairwise(row_inds):
+                for cs, cs_next in itertools.pairwise(col_inds):
                     ps = [
                         # +1 ensures we share edges between polygons
                         cbook._array_perimeter(a[rs:rs_next+1, cs:cs_next+1])
@@ -3385,7 +3385,7 @@ def permutation_matrices(n):
                         voxel_faces[i0].append(p0 + square_rot_neg)
 
                     # draw middle faces
-                    for r1, r2 in zip(rinds[:-1], rinds[1:]):
+                    for r1, r2 in itertools.pairwise(rinds):
                         p1 = permute.dot([p, q, r1])
                         p2 = permute.dot([p, q, r2])