python os.walk traversal problem

walk_traversal_problem.py

#!/usr/bin/python3

"""
os.walk traversal problem

"""

import os
import sys
import logging
import tempfile


def _error(exc):
    raise exc


def test_walk_recursion_limit():
    " os.walk has to raise RecursionError "

    tmpdirname = tempfile.mkdtemp(prefix='python-walk-test-')
    os.chdir(tmpdirname)

    for _ in range(sys.getrecursionlimit() + 1):
        os.mkdir('x')
        os.chdir('x')

    os.chdir(tmpdirname)

    for _ in os.walk(tmpdirname, onerror=_error):
        pass


def test_walk_file_name_too_long():
    " os.walk has to raise OSError(36, 'File name too long') "

    tmpdirname = tempfile.mkdtemp(prefix='python-walk-test-')
    os.chdir(tmpdirname)

    names = []

    while True:
        name = 'x' * 10
        names.append(name)
        os.mkdir(name)
        os.chdir(name)

        full_path = os.path.join(tmpdirname, os.sep.join(names))
        if len(full_path) > os.pathconf(tmpdirname, 'PC_PATH_MAX'):
            break

    os.chdir(tmpdirname)

    for _ in os.walk(tmpdirname, onerror=_error):
        pass


try:
    test_walk_recursion_limit()
except RecursionError as e:
    logging.error(e)

try:
    test_walk_file_name_too_long()
except OSError as e:
    logging.error(e.strerror)