[SOLVED] Python: chmod is NOT preventing file from being deleted

Issue

I'm setting the mode on a file to try to prevent it being deletable, but nothing seems to work. Example:

import os
from stat import S_IRUSR, S_IRGRP, S_IROTH

with tempfile.TemporaryDirectory() as local_dir:
    local_file = os.path.join(local_dir, 'a.txt')
    with open(local_file, 'wt') as f:
        f.writelines('some stuff')
    os.chmod(local_file, S_IRUSR|S_IRGRP|S_IROTH)
    print(oct(os.stat(local_file).st_mode)[-3:])  # prints '444' as expected
    os.remove(local_file)  # no exception
    print(os.path.isfile(local_file)) # prints False, the file has been deleted

Solution

Running chmod on a file cannot render a file non-deletable. There is no "deletable/not deletable" mode bit.

A user's permissions for a file have no effect on whether they can delete that file. To delete a file, a user needs write and execute permissions on the containing directory.

Answered By - user2357112

Answer Checked By - Marie Seifert (WPSolving Admin)