# {fas}`info-circle` Advanced Requests Following are some tips on using requests-cache with some of the more [advanced features](https://requests.readthedocs.io/en/latest/user/advanced/) of the requests library. ## Event Hooks Requests has an [event hook](https://requests.readthedocs.io/en/latest/user/advanced/#event-hooks) system that can be used to add custom behavior into different parts of the request process. It can be used, for example, for request throttling: :::{dropdown} Example :animate: fade-in-slide-down :color: primary :icon: file-code ```python >>> import time >>> import requests >>> from requests_cache import CachedSession >>> def make_throttle_hook(timeout=1.0): >>> """Make a request hook function that adds a custom delay for non-cached requests""" >>> def hook(response, *args, **kwargs): >>> if not getattr(response, 'from_cache', False): >>> print('sleeping') >>> time.sleep(timeout) >>> return response >>> return hook >>> session = CachedSession() >>> session.hooks['response'].append(make_throttle_hook(0.1)) >>> # The first (real) request will have an added delay >>> session.get('https://httpbin.org/get') >>> session.get('https://httpbin.org/get') ``` ::: ## Streaming Requests If you use [streaming requests](https://requests.readthedocs.io/en/latest/user/advanced/#id9), you can use the same code to iterate over both cached and non-cached requests. Cached response content will have already been read (i.e., consumed), but will be available for re-reading so it behaves like the original streamed response: :::{dropdown} Example :animate: fade-in-slide-down :color: primary :icon: file-code ```python >>> from requests_cache import CachedSession >>> session = CachedSession() >>> for i in range(2): ... response = session.get('https://httpbin.org/stream/20', stream=True) ... for chunk in response.iter_lines(): ... print(chunk.decode('utf-8')) ``` :::