What Is the 429 Status Code? (429 Too Many Requests)

import time, random, requests
from email.utils import parsedate_to_datetime
from datetime import datetime, timezone

HEADERS = {  # a real browser UA — the default python-requests UA invites 429s
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                  "AppleWebKit/537.36 (KHTML, like Gecko) "
                  "Chrome/124.0 Safari/537.36",
    "Accept": "text/html,application/json",
    "Accept-Language": "en-US,en;q=0.9",
}

def retry_after_seconds(resp):
    """Honor Retry-After whether it's seconds or an HTTP date."""
    ra = resp.headers.get("Retry-After")
    if not ra:
        return None
    if ra.isdigit():
        return int(ra)
    try:
        when = parsedate_to_datetime(ra)
        return max(0, (when - datetime.now(timezone.utc)).total_seconds())
    except (TypeError, ValueError):
        return None

def get_with_backoff(url, max_retries=5):
    session = requests.Session()
    session.headers.update(HEADERS)
    for attempt in range(max_retries):
        resp = session.get(url, timeout=30)
        if resp.status_code != 429:
            return resp
        wait = retry_after_seconds(resp)
        if wait is None:                       # no header -> exponential backoff
            wait = (2 ** attempt) + random.uniform(0, 1)  # + jitter
        print(f"429 received; waiting {wait:.1f}s (attempt {attempt + 1})")
        time.sleep(wait)
    raise RuntimeError("Still rate-limited after retries -- rotate proxies")

resp = get_with_backoff("https://example.com/api")
print(resp.status_code, len(resp.text))