def dl_file(url, dest, chunk_size=6553):
    """Download `url` to `dest`"""
    import urllib3
    http = urllib3.PoolManager()
    r = http.request('GET', url, preload_content=False)
    with dest.open('wb') as out:
        while True:
            data = r.read(chunk_size)
            if data is None or len(data) == 0:
                break
            out.write(data)
    r.release_conn()
Download `url` to `dest`