fix.txt

Original error happens on line 11, that exit_ok was default to be False which caused the file_exist erorr, I made the change to set it to be True.
Also added a docstring for the download_file function.

sample.py

import os
import urllib.request
from urllib.parse import urlparse


def download_file(url, cachedir=None, ignorecache=False, filename=None) -> str:
"""download_file would create a directory if not exist, then download the file to directory"""
    if not cachedir:
        cachedir = os.path.join(os.getcwd(), "build")

    os.makedirs(cachedir,exit_ok=True)

    if not filename:
        filename = os.path.basename(urlparse(url).path)

    path = os.path.join(cachedir, filename)
    
    if ignorecache or not os.path.exists(path):
        urllib.request.urlretrieve(url, path)

    return path
    
if __name__ == "__main__":
dlpath = download_file("http://pantry.learningequality.org/downloads/ka-lite/0.16/content/contentpacks/en.zip")