3.11. Event Hooks

Requests has a hook system that you can use to manipulate portions of the request process, or signal event handling.

Available hooks:

response:

The response generated from a Request.

You can assign a hook function on a per-request basis by passing a {hook_name: callback_function} dictionary to the hooks request parameter:

hooks=dict(response=print_url)

That callback_function will receive a chunk of data as its first argument.

def print_url(r, *args, **kwargs):
    print(r.url)

If an error occurs while executing your callback, a warning is given.

If the callback function returns a value, it is assumed that it is to replace the data that was passed in. If the function doesn’t return anything, nothing else is effected.

Let’s print some request method arguments at runtime:

>>> requests.get('http://httpbin.org', hooks=dict(response=print_url))
http://httpbin.org
<Response [200]>