Replace short links in text to full links

gistfile1.py

import requests
import re

DOMAINS = ['bit.ly']
PATTERN = 'https?://{}/\w+'

def expand_short_url(short_url):
    resp = requests.get(short_url, allow_redirects=False)
    return resp.headers['location']
    
def replace_short_urls(text):
    for domain in (
        domain
        for domain in DOMAINS
        if domain in text
    ):
        pattern = PATTERN.format(domain)
        text = re.sub(pattern, lambda m: expand_short_url(m.group(0)), text)
    return text