如何在抓取时修复429请求过多

import random, time
import requests

USER, PASS, HOST = "USER", "PASS", "proxy.s4m.online"
POOL = [
    f"socks5h://{USER}:{PASS}@{HOST}:1080",
    f"http://{USER}:{PASS}@{HOST}:3128",
]

def polite_get(url, max_tries=6):
    for attempt in range(1, max_tries + 1):
        proxy = random.choice(POOL)
        r = requests.get(url, proxies={"http": proxy, "https": proxy},
                         timeout=(5, 20))
        if r.status_code != 429:
            r.raise_for_status()
            return r

        # 429: prefer the server's Retry-After, else exponential backoff
        retry_after = r.headers.get("Retry-After")
        if retry_after and retry_after.isdigit():
            wait = int(retry_after)
        else:
            wait = min(2 ** attempt, 60) + random.random()  # cap + jitter

        print(f"[{attempt}/{max_tries}] 429; waiting {wait:.1f}s")
        time.sleep(wait)

    raise SystemExit(f"still rate-limited after {max_tries} tries")

# Global throttle: cap how fast you fire, independent of retries.
MIN_INTERVAL = 0.5  # seconds between requests per worker
_last = 0.0
def throttled_get(url):
    global _last
    delta = time.time() - _last
    if delta < MIN_INTERVAL:
        time.sleep(MIN_INTERVAL - delta)
    _last = time.time()
    return polite_get(url)

print(throttled_get("https://httpbin.org/status/200").status_code)