Missing empty continue branch during iteration

[ofek]

Reproduce

System

Python 3.8.1 (tags/v3.8.1:1b293b6, Dec 18 2019, 23:11:46) [MSC v.1916 64 bit (AMD64)] on win32

File

cov-bug.py

from pathlib import Path
from tempfile import TemporaryDirectory
from typing import Generator, List


def recurse_artifacts(artifacts: List[str], root: Path) -> Generator[Path, None, None]:
    for artifact in artifacts:
        artifact = Path(artifact)
        if not artifact.is_absolute():
            artifact = root / artifact

        if artifact.is_file():
            yield artifact
        elif artifact.is_dir():
            yield from artifact.iterdir()


def main():
    with TemporaryDirectory() as d:
        project_dir = Path(d).resolve()
        build_dir = project_dir / 'dist'
        build_dir.mkdir()

        absolute_path = project_dir / 'absolute.whl'
        absolute_path.touch()
        (build_dir / 'test.tar.gz').touch()
        (build_dir / 'test.txt').touch()
        (build_dir / 'test.whl').touch()

        # Turning generator into list also fails:
        # for artifact in list(recurse_artifacts(['dist', str(absolute_path)], project_dir)):
        for artifact in recurse_artifacts(['dist', str(absolute_path)], project_dir):
            if artifact.name.endswith('.whl'):
                print('found wheel')
            elif artifact.name.endswith('.tar.gz'):
                print('found sdist')
            else:
                # print('skipping')
                continue

            print('uploading')


if __name__ == '__main__':
    main()

Command

$ coverage run cov-bug.py && coverage report --show-missing
found sdist
uploading
found wheel
uploading
found wheel
uploading
Name         Stmts   Miss  Cover   Missing
------------------------------------------
cov-bug.py      31      1    97%   39
------------------------------------------
TOTAL           31      1    97%

Additional context

The branch is discovered if you uncomment print('skipping')

[nedbat]

This was a long-standing issue with CPython, and a duplicate of #198. It's now fixed in CPython 3.10.

[ofek]

My bad, thanks!