python 3.8 fixes

lib/elements/satin_column.py

@@ -6,6 +6,7 @@
 from copy import deepcopy
 import itertools
 from itertools import chain
+import typing
 
 import numpy as np
 from inkex import paths
@@ -769,7 +770,7 @@ class SatinColumn(EmbroideryElement):
                 distance_remaining -= segment_length
                 pos = segment_end
 
-    def plot_points_on_rails(self, spacing, offset_px=(0, 0), offset_proportional=(0, 0), use_random=False) -> list[tuple[Point, Point]]:
+    def plot_points_on_rails(self, spacing, offset_px=(0, 0), offset_proportional=(0, 0), use_random=False) -> typing.List[typing.Tuple[Point, Point]]:
         # Take a section from each rail in turn, and plot out an equal number
         # of points on both rails.  Return the points plotted. The points will
         # be contracted or expanded by offset using self.offset_points().

lib/stitches/running_stitch.py

@@ -4,6 +4,7 @@
 # Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
 
 import math
+import typing
 from copy import copy
 
 import numpy as np
@@ -13,7 +14,7 @@ from ..utils import prng
 """ Utility functions to produce running stitches. """
 
 
-def split_segment_even_n(a, b, segments: int, jitter_sigma: float = 0.0, random_seed: str | None = None) -> list[shgeo.Point]:
+def split_segment_even_n(a, b, segments: int, jitter_sigma: float = 0.0, random_seed=None) -> typing.List[shgeo.Point]:
     if segments <= 1:
         return []
     line = shgeo.LineString((a, b))
@@ -27,13 +28,13 @@ def split_segment_even_n(a, b, segments: int, jitter_sigma: float = 0.0, random_
     return [line.interpolate(x, normalized=True) for x in sorted(splits)]
 
 
-def split_segment_even_dist(a, b, max_length: float, jitter_sigma: float = 0.0, random_seed: str | None = None) -> list[shgeo.Point]:
+def split_segment_even_dist(a, b, max_length: float, jitter_sigma: float = 0.0, random_seed=None) -> typing.List[shgeo.Point]:
     distance = shgeo.Point(a).distance(shgeo.Point(b))
     segments = math.ceil(distance / max_length)
     return split_segment_even_n(a, b, segments, jitter_sigma, random_seed)
 
 
-def split_segment_random_phase(a, b, length: float, length_sigma: float, random_seed: str) -> list[shgeo.Point]:
+def split_segment_random_phase(a, b, length: float, length_sigma: float, random_seed: str) -> typing.List[shgeo.Point]:
     line = shgeo.LineString([a, b])
     progress = length * prng.uniformFloats(random_seed, "phase")[0]
     splits = [progress]