Functions to add file permissions with Python.

chmod.py

# coding:  utf-8

"""Provides functions to add file permissions.

read:
stat.S_IRUSR
stat.S_IRGRP
stat.S_IROTH

write:
stat.S_IWUSR
stat.S_IWGRP
stat.S_IWOTH

execute:
stat.S_IXUSR
stat.S_IXGRP
stat.S_IXOTH
"""

import stat
from pathlib import Path


def main():
    """Test the functions."""
    add_read_permission(Path('sample1.txt'), 'go')
    add_write_permission(Path('sample2.txt'), 'o')
    add_execute_permission(Path('sample3.py'), 'ug')


def add_read_permission(path: Path, target: str = 'u'):
    """Add `r` (`read`) permission to specified targets."""
    mode_map = {
        'u': stat.S_IRUSR,
        'g': stat.S_IRGRP,
        'o': stat.S_IROTH,
        'a': stat.S_IRUSR | stat.S_IRGRP | stat.S_IROTH,
    }

    mode = path.stat().st_mode
    for t in target:
        mode |= mode_map[t]

    path.chmod(mode)


def add_write_permission(path: Path, target: str = 'u'):
    """Add `w` (`write`) permission to specified targets."""
    mode_map = {
        'u': stat.S_IWUSR,
        'g': stat.S_IWGRP,
        'o': stat.S_IWOTH,
        'a': stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH,
    }

    mode = path.stat().st_mode
    for t in target:
        mode |= mode_map[t]

    path.chmod(mode)


def add_execute_permission(path: Path, target: str = 'u'):
    """Add `x` (`execute`) permission to specified targets."""
    mode_map = {
        'u': stat.S_IXUSR,
        'g': stat.S_IXGRP,
        'o': stat.S_IXOTH,
        'a': stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH,
    }

    mode = path.stat().st_mode
    for t in target:
        mode |= mode_map[t]

    path.chmod(mode)


if __name__ == '__main__':
    main()