blob: 875c0fbaae98c1b0a667f463af21f6f17a0bb1f9 [file] [log] [blame]
import argparse
import io
import tokenize
from tokenize import tokenize as tokenize_tokenize
from typing import Optional
from typing import Sequence
NON_CODE_TOKENS = frozenset((
tokenize.COMMENT, tokenize.ENDMARKER, tokenize.NEWLINE, tokenize.NL,
def check_docstring_first(src: bytes, filename: str = '<unknown>') -> int:
"""Returns nonzero if the source has what looks like a docstring that is
not at the beginning of the source.
A string will be considered a docstring if it is a STRING token with a
col offset of 0.
found_docstring_line = None
found_code_line = None
tok_gen = tokenize_tokenize(io.BytesIO(src).readline)
for tok_type, _, (sline, scol), _, _ in tok_gen:
# Looks like a docstring!
if tok_type == tokenize.STRING and scol == 0:
if found_docstring_line is not None:
f'{filename}:{sline} Multiple module docstrings '
f'(first docstring on line {found_docstring_line}).',
return 1
elif found_code_line is not None:
f'{filename}:{sline} Module docstring appears after code '
f'(code seen on line {found_code_line}).',
return 1
found_docstring_line = sline
elif tok_type not in NON_CODE_TOKENS and found_code_line is None:
found_code_line = sline
return 0
def main(argv: Optional[Sequence[str]] = None) -> int:
parser = argparse.ArgumentParser()
parser.add_argument('filenames', nargs='*')
args = parser.parse_args(argv)
retv = 0
for filename in args.filenames:
with open(filename, 'rb') as f:
contents =
retv |= check_docstring_first(contents, filename=filename)
return retv