feat(compatibility): Python3.8 compatibility

.travis.yml

@@ -1,7 +1,9 @@
 dist: bionic
 sudo: false
 language: python
-python: 3.9
+python:
+  - 3.9
+  - 3.8
 cache:
   directories:
   - "$HOME/.cache/pip"

prototorch/utils/utils.py

@@ -1,8 +1,12 @@
 """ProtoFlow utilities"""
 
 import warnings
-from collections.abc import Iterable
-from typing import Union
+from typing import (
+    Dict,
+    Iterable,
+    List,
+    Union,
+)
 
 import numpy as np
 import torch
@@ -24,7 +28,7 @@ def mesh2d(x=None, border: float = 1.0, resolution: int = 100):
     return mesh, xx, yy
 
 
-def distribution_from_list(list_dist: list[int],
+def distribution_from_list(list_dist: List[int],
                            clabels: Iterable[int] = None):
     clabels = clabels or list(range(len(list_dist)))
     distribution = dict(zip(clabels, list_dist))
@@ -32,7 +36,7 @@ def distribution_from_list(list_dist: list[int],
 
 
 def parse_distribution(user_distribution,
-                       clabels: Iterable[int] = None) -> dict[int, int]:
+                       clabels: Iterable[int] = None) -> Dict[int, int]:
     """Parse user-provided distribution.
 
     Return a dictionary with integer keys that represent the class labels and

setup.py

@@ -59,7 +59,7 @@ setup(
     url=PROJECT_URL,
     download_url=DOWNLOAD_URL,
     license="MIT",
-    python_requires=">=3.9",
+    python_requires=">=3.8",
     install_requires=INSTALL_REQUIRES,
     extras_require={
         "datasets": DATASETS,