multiprocessing.pool.RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 121, in worker
    result = (True, func(*args, **kwds))
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 44, in mapstar
    return list(map(*args))
  File "./src/task3.py", line 263, in classify
    cat = infer_category_from_base_url(base_url, lang)
  File "./src/task3.py", line 99, in infer_category_from_base_url
    k for k,v in CATEGORIES_URL_KEYWORDS.items()
  File "./src/task3.py", line 100, in <listcomp>
    if any(e in base_url_parts for e in v[lang])
KeyError: None
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "./src/main.py", line 55, in <module>
    run()
  File "./src/main.py", line 44, in run
    tasks_functions[task](source_dir, output_dir, print_to_stdout)
  File "./src/task3.py", line 304, in run_categories_task
    p.map(classify_fun, html_files_generator)
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 268, in map
    return self._map_async(func, iterable, mapstar, chunksize).get()
  File "/usr/lib/python3.7/multiprocessing/pool.py", line 657, in get
    raise self._value
KeyError: None