Check more flake8 in pre-commit

Right now we use a small subset of flake8 in pre-commit. Given that pre-commit runs primarily on PR diffs, it seems fine to check for more problems. There are hundreds of violations of the full flake8 checks, so I think we should sequentially add codes to pre-commit to keep correction PRs small (the PRs should either fix the problems and/or add the appropriate noqa).

PRs TODO

• F401 : module imported but unused (#13853)
• F402 : import module from line N shadowed by loop variable (#13853)
• F403 ‘from module import *’ used; unable to detect undefined names
• F404 : future import(s) name after other statements (#13853)
• F405 : name may be undefined, or defined from star imports: module (#13853)
• F406 : ‘from module import *’ only allowed at module level (#13853)
• F407 : an undefined future feature name was imported (#13853)
• F501 : invalid % format literal (#13853)
• F502 : % format expected mapping but got sequence (#13853)
• F503 : % format expected sequence but got mapping (#13853)
• F504 : % format unused named arguments (#13853)
• F505 : % format missing named arguments (#13853)
• F506 : % format mixed positional and named arguments (#13853)
• F507 : % format mismatch of placeholder and argument count (#13853)
• F508 : % format with * specifier requires a sequence (#13853)
• F509 : % format with unsupported format character (#13853)
• F521 : .format(…) invalid format string
• F522 : .format(…) unused named arguments
• F523 : .format(…) unused positional arguments
• F524 : .format(…) missing argument
• F525 : .format(…) mixing automatic and manual numbering
• F541 : f-string without any placeholders
• F601 : dictionary key name repeated with different values
• F602 : dictionary key variable name repeated with different values
• F621 : too many expressions in an assignment with star-unpacking
• F622 : two or more starred expressions in an assignment (a, *b, *c = d)
• F631 : assertion test is a tuple, which is always True
• F632 : use ==/!= to compare str, bytes, and int literals
• F633 : use of >> is invalid with print function
• F634 : if test is a tuple, which is always True
• F701 : a break statement outside of a while or for loop (#13853)
• F702 : a continue statement outside of a while or for loop (#13853)
• F703 : a continue statement in a finally block in a loop (#13853)
• F704 : a yield or yield from statement outside of a function (#13853)
• F706 : a return statement outside of a function/method (#13853)
• F707 : an except: block as not the last exception handler (#13853)
• F721 : syntax error in doctest
• F722 : syntax error in forward annotation
• F723 : syntax error in type comment
• F811 : redefinition of unused name from line N
• F821 : undefined name name
• F822 : undefined name name in all
• F823 : local variable name … referenced before assignment
• F831 : duplicate argument name in function definition
• F841 : local variable name is assigned to but never used
• F901 : raise NotImplemented should be raise NotImplementedError (#13853)
• C901
• E101 | indentation contains mixed spaces and tabs
• E111 | indentation is not a multiple of four
• E112 | expected an indented block
• E113 | unexpected indentation
• E114 | indentation is not a multiple of four (comment)
• E115 | expected an indented block (comment)
• E116 | unexpected indentation (comment)
• E117 | over-indented
• E121 (*^) | continuation line under-indented for hanging indent
• E122 (^) | continuation line missing indentation or outdented
• E123 (*) | closing bracket does not match indentation of opening bracket’s line
• E124 (^) | closing bracket does not match visual indentation
• E125 (^) | continuation line with same indent as next logical line
• E126 (*^) | continuation line over-indented for hanging indent
• E127 (^) | continuation line over-indented for visual indent
• E128 (^) | continuation line under-indented for visual indent
• E129 (^) | visually indented line with same indent as next logical line
• E131 (^) | continuation line unaligned for hanging indent
• E133 (*) | closing bracket is missing indentation
• E201 | whitespace after ‘(’
• E202 | whitespace before ‘)’
• E203 | whitespace before ‘,’, ‘;’, or ‘:’
• E211 | whitespace before ‘(’
• E221 | multiple spaces before operator
• E222 | multiple spaces after operator
• E223 | tab before operator
• E224 | tab after operator
• E225 | missing whitespace around operator
• E226 (*) | missing whitespace around arithmetic operator
• E227 | missing whitespace around bitwise or shift operator
• E228 | missing whitespace around modulo operator
• E231 | missing whitespace after ‘,’, ‘;’, or ‘:’
• E241 (*) | multiple spaces after ‘,’
• E242 (*) | tab after ‘,’
• E251 | unexpected spaces around keyword / parameter equals
• E261 | at least two spaces before inline comment
• E262 | inline comment should start with ‘# ‘
• E265 | block comment should start with ‘# ‘
• E266 | too many leading ‘#’ for block comment
• E271 | multiple spaces after keyword
• E272 | multiple spaces before keyword
• E273 | tab after keyword
• E274 | tab before keyword
• E275 | missing whitespace after keyword
• E301 | expected 1 blank line, found 0
• E302 | expected 2 blank lines, found 0
• E303 | too many blank lines (3)
• E304 | blank lines found after function decorator
• E305 | expected 2 blank lines after end of function or class
• E306 | expected 1 blank line before a nested definition
• E401 | multiple imports on one line
• E402 | module level import not at top of file
• E501 (^) | line too long (82 > 79 characters)
• E502 | the backslash is redundant between brackets
• E701 | multiple statements on one line (colon)
• E702 | multiple statements on one line (semicolon)
• E703 | statement ends with a semicolon
• E704 (*) | multiple statements on one line (def)
• E711 (^) | comparison to None should be ‘if cond is None:’
• E712 (^) | comparison to True should be ‘if cond is True:’ or ‘if cond:’
• E713 | test for membership should be ‘not in’
• E714 | test for object identity should be ‘is not’
• E721 (^) | do not compare types, use ‘isinstance()’
• E722 | do not use bare except, specify exception instead
• E731 | do not assign a lambda expression, use a def
• E741 | do not use variables named ‘l’, ‘O’, or ‘I’
• E742 | do not define classes named ‘l’, ‘O’, or ‘I’
• E743 | do not define functions named ‘l’, ‘O’, or ‘I’
• E901 | SyntaxError or IndentationError
• E902 | IOError
• E999
• W191 | indentation contains tabs
• W291 | trailing whitespace
• W292 | no newline at end of file
• W293 | blank line contains whitespace
• W391 | blank line at end of file
• W503 (*) | line break before binary operator
• W504 (*) | line break after binary operator
• W505 (*^) | doc line too long (82 > 79 characters)
• W605 | invalid escape sequence ‘x’
• W606 | ‘async’ and ‘await’ are reserved keywords starting with Python 3.7

[WilliamJamieson]

After doing some of the simpler sub-packages, yes I agree.

[saimn]

@nstarman - Sure, one of the benefit of using black is that the formatting should then be pep8 compliant, except maybe a few specific cases. So I guess once black has been applied we could switch to a flake8 config where we just exclude a few rules.