How to pass parameters to hooks in python grequests

Question

According the Requests documentation, event hooks can be added to .get() function.

requests.get('http://httpbin.org', hooks=dict(response=print_url))
def print_url(r, *args, **kwargs):
    print(r.url)

This is fine but how to set *args with custom parameters, for example, I want to pass some custom values to print_url(), how to set those in *args ? Something like this fails :

args = ("search_item", search_item)
rs = (grequests.get(u, hooks={'response': [parse_books],'args': [args]}) for u in urls)

score 17 · Accepted Answer · answered Aug 04 '14 at 20:20

17

You cannot specify extra arguments to pass to a response hook. If you want extra information to be specified you should make a function that you call which then returns a function to be passed as a hook, e.g.,

def hook_factory(*factory_args, **factory_kwargs):
    def response_hook(response, *request_args, **request_kwargs):
        # use factory_kwargs
        # etc.
        return None # or the modified response
    return response_hook

grequests.get(u, hooks={'response': [hook_factory(search_item=search_item)]})

answered Aug 04 '14 at 20:20

Ian Stapleton Cordasco

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Though this method works sometimes, I see the following exception:AttributeError: 'list' object has no attribute 'history' >(stream=False)> failed with AttributeError – Ved Aug 11 '14 at 16:56
@Ved if you have a new question you should ask a new question – Ian Stapleton Cordasco Aug 11 '14 at 20:23
My comment was not a question but an attempt to complete the discussion. Thanks for pointing out by the way – Ved Aug 13 '14 at 05:15
I have concerns that *factory_args wont be matching with parameters in request. At least it have not worked out in my implementation – Ayrat Jun 02 '15 at 17:03
@aryat you have a different use case so you need to make a new question – Ian Stapleton Cordasco Jun 02 '15 at 17:08

score 2 · Answer 2 · answered Jan 10 '15 at 07:35

the response_hook function has to return a response-object. the simplest workaround would be to modify the respose object you get from the hook_factory calling the hook.

def response_hook(response, *request_args, **request_kwargs):
    # use factory_kwargs
    # etc.
    response.meta1='meta1' #add data 
    response.meta2='meta2'

    #etc.

    return response# or the modified response

return response_hook

hope this helps.

How to pass parameters to hooks in python grequests

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