Current master branch doesn't pass the flake8 test due to its automatic update. This PR fixes code to pass flake8 v6.1.0 test.
$ flake8 pfio tests
tests/v2_tests/test_fs.py:87:16: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`
tests/v2_tests/test_s3_zip.py:29:48: E231 missing whitespace after ','
tests/v2_tests/test_s3_zip.py:160:48: E231 missing whitespace after ','
Current master branch doesn't pass the flake8 test due to its automatic update. This PR fixes code to pass flake8 v6.1.0 test.