Download and cache file

cache-file.py

#!/usr/bin/env python3
import sys
from pathlib import Path
from urllib.request import urlretrieve

import requests
from appdirs import user_cache_dir
from tqdm import tqdm

cache_dir = Path(user_cache_dir('programm-name', 'dein-name'))
filename = 'bigfile.bin'

url = 'http://example.com/' + filename
file_path = cache_dir / filename

if not file_path.is_file():
    print('downloading', repr(url), 'to cache', repr(file_path), file=sys.stderr)
    r = requests.get(url, stream=True)
    total_size = int(r.headers.get('content-length', 0))

    with file_path.open('wb') as f:
        progressbar = tqdm(r.iter_content(32*1024), total=total_size, unit='B', unit_scale=True)
        for data in progressbar:
            f.write(data)

with file_path.open('r'):
    ...