How to Handle Retry-After Header in Python

```python
import time
from datetime import datetime, timedelta


class RetryAfterHandler:
    def __init__(self, max_retries=3):
        self.max_retries = max_retries

    def get_retry_after_seconds(self, response_headers):
        retry_after_value = response_headers.get("Retry-After")
        if retry_after_value is None:
            return None

        try:
            return int(retry_after_value)
        except ValueError:
            try:
                retry_time = datetime.fromisoformat(retry_after_value)
                return max(0, int((retry_time - datetime.now()).total_seconds()))
            except ValueError:
                return None

    def retry_with_delay(self, request_func, response_headers):
        for attempt in range(self.max_retries):
            result = request_func()
            if not result.get("rate_limited"):
                return result

            seconds = self.get_retry_after_seconds(response_headers)
            if seconds is None:
                seconds = 5  # default delay if header is invalid

            print(f"Rate limited (attempt {attempt + 1}/{self.max_retries}), waiting {seconds}s...")
            time.sleep(seconds)

        return {"error": "Max retries exceeded"}


def mock_rate_limited_request():
    """Simulates a rate-limited response"""
    return {"rate_limited": True, "data": None}


def mock_success_request():
    """Simulates a successful response after a delay"""
    return {"rate_limited": False, "data": "ok"}


if __name__ == "__main__":
    handler = RetryAfterHandler(max_retries=2)

    # Example 1: numeric Retry-After header
    headers = {"Retry-After": "2"}
    result = handler.retry_with_delay(mock_rate_limited_request, headers)
    print(f"Result: {result}")

    # Example 2: HTTP date format Retry-After header
    future_time = datetime.now() + timedelta(seconds=3)
    headers = {"Retry-After": future_time.isoformat()}
    result = handler.retry_with_delay(mock_success_request, headers)
    print(f"Result: {result}")