Import ABC from collections.abc explicitly.

[tirkarthi]

Directly accessing abc module from collections raises error. This worked since one of the other modules would have import collections.abc

python                                                       
Python 3.9.0b5 (default, Jul 20 2020, 20:46:56) 
[GCC 7.5.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import collections
>>> collections.abc.Mapping
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.9/collections/__init__.py", line 68, in __getattr__
    raise AttributeError(f'module {__name__!r} has no attribute {name!r}')
AttributeError: module 'collections' has no attribute 'abc'

[maartenbreddels]

Thanks!