Como usar proxies com solicitações Python

import random
import requests
from requests.exceptions import RequestException

# --- Credentials & endpoints (replace with your s4m.online proxy user) ---
USER = "USER"
PASS = "PASS"
HOST = "proxy.s4m.online"

# SOCKS5 with REMOTE DNS (socks5h) — needs: pip install "requests[socks]"
SOCKS5 = f"socks5h://{USER}:{PASS}@{HOST}:1080"
# Plain HTTP CONNECT proxy — works with a stock requests install
HTTP   = f"http://{USER}:{PASS}@{HOST}:3128"

def proxies_for(proxy_url):
    # The "http"/"https" keys are the scheme of the TARGET url,
    # not the proxy's protocol — both can point at one proxy.
    return {"http": proxy_url, "https": proxy_url}

def check_ip(session, proxy):
    r = session.get(
        "https://api.ipify.org?format=json",
        proxies=proxies_for(proxy),
        timeout=(5, 15),   # (connect, read) seconds
    )
    r.raise_for_status()
    return r.json()["ip"]

# --- Per-session config: pools connections, keeps cookies/headers ---
with requests.Session() as s:
    s.headers.update({"User-Agent": "s4m-example/1.0"})
    print("Exit IP:", check_ip(s, SOCKS5))

# --- Rotate across a list, retrying on failure ---
POOL = [SOCKS5, HTTP]

def fetch(url, retries=3):
    last_err = None
    for attempt in range(1, retries + 1):
        proxy = random.choice(POOL)
        try:
            with requests.Session() as s:
                r = s.get(url, proxies=proxies_for(proxy), timeout=(5, 15))
                r.raise_for_status()
                return r
        except RequestException as e:
            last_err = e
            print(f"[{attempt}/{retries}] {proxy} failed: {e}")
    raise last_err

resp = fetch("https://httpbin.org/ip")
print(resp.json())