Support python 3.7

[VinhLoiIT]

Is your feature request related to a problem? Please describe.
I mainly use anomalib on Google Colab but it only supports python=3.7 at the moment. There is an error when running the training command:
python -m tools.train --model_config_path path/to/config.yaml

The error was:

Traceback (most recent call last):
  File "/usr/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/content/anomalib/tools/train.py", line 66, in <module>
    train()
  File "/content/anomalib/tools/train.py", line 55, in train
    model = get_model(config)
  File "/content/anomalib/anomalib/models/__init__.py", line 61, in get_model
    module = import_module(f"anomalib.models.{config.model.name}.model")
  File "/usr/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/content/anomalib/anomalib/models/stfpm/__init__.py", line 17, in <module>
    from .model import (  # noqa # pylint: disable=unused-import
  File "/content/anomalib/anomalib/models/stfpm/model.py", line 31, in <module>
    from anomalib.data.tiler import Tiler
  File "/content/anomalib/anomalib/data/tiler.py", line 19, in <module>
    from typing import Optional, Sequence, SupportsIndex, Tuple, Union
ImportError: cannot import name 'SupportsIndex' from 'typing' (/usr/lib/python3.7/typing.py)

Suggestion
AFAIK, SupportsIndex is used for type-hint of classes that have __item__ method, but the default value doesn't seem right and int is better.

After making the below modification:

diff --git a/anomalib/data/tiler.py b/anomalib/data/tiler.py
index 5a274c2..d061337 100644
--- a/anomalib/data/tiler.py
+++ b/anomalib/data/tiler.py
@@ -16,7 +16,7 @@
 
 from itertools import product
 from math import ceil
-from typing import Optional, Sequence, SupportsIndex, Tuple, Union
+from typing import Optional, Sequence, Tuple, Union
 
 import torch
 import torchvision.transforms as T
@@ -161,7 +161,7 @@ class Tiler:
         stride: Union[int, Sequence],
         remove_border_count: int = 0,
         mode: str = "padding",
-        tile_count: SupportsIndex = 4,
+        tile_count: int = 4,
     ) -> None:
 
         self.tile_size_h, self.tile_size_w = self.__validate_size_type(tile_size)

The code works well.

I did not have further investigation, e.g. checking dependencies, other models, etc; but I think supporting python 3.7 is possible with minimal changes. I ran with the STFMP model.

[samet-akcay]

Hi @VinhLoiIT, thank you for your suggestion! We'll try to test the 3.7 support

[samet-akcay]

@VinhLoiIT your proposed changes have been added the development branch. I'm therefore closing this.