I have raised one more PR; I think i am done with this issue. People who are interested can take up from here. ,

For the record, following are some filters to search;

Query to find unused imports
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find . -type f -name \*.py -print  | xargs flake8 | grep F401
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Search query 
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grep -v warnings | grep -v "\.\*" | grep -v tkinter | grep -v sysconfig | grep -v readline | grep -v py3_test_grammar.py  | grep -v java | grep -v rlcompleter | grep -v sitecustomize | grep -v __all__ | grep -v test_importlib | grep -v async | grep -v test_future | grep -v circular_import | grep -v dataclasses
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