import os

import requests

proxies = {"http": os.environ["PROXY_URL"], "https": os.environ["PROXY_URL"]}
with requests.get("https://example.com/", proxies=proxies, stream=True) as r:
    wire = r.raw.read(decode_content=False)  # body bytes as sent, still encoded
    print(r.headers.get("content-encoding"), len(wire))