CODEWITHSUNDEEP
pythontwisted
Crolle
Crolle

Reputation: 832

Twisted Agent won't build request from bytes

I'm learning Twisted by trying to build an RSS agregator. When I try to build requests using the web agent, I'm told that I did not provide the url argument as bytes :

[Failure instance: Traceback (failure with no frames): <class 'twisted.web._newclient.RequestGenerationFailed'>: [<twisted.python.failure.Failure builtins.TypeError: sequence item 0: expected a bytes-like object, str found>]

But I think I did :

from twisted.internet import reactor
from twisted.web.client import Agent

def request_sent(response):
    print ('I got something!')

def request_failed(reason):
    print (reason)

def feed_loader_main():
    """
    Starts and manage the reactor
    """
    agent = Agent(reactor)

    d = agent.request(
        'GET',
        'http://www.example.com'.encode('utf8')   ##### <- HERE
    )

    d.addCallback(request_sent)
    d.addErrback(request_failed)

    print ('Firing reactor!')
    reactor.run()

if __name__ == '__main__':
    feed_loader_main()

Is it Twisted black magic going on here or just poor encoding from me?

Upvotes: 1

Views: 871

Answers (1)

Jean-Paul Calderone
Jean-Paul Calderone

Reputation: 48335

The exception didn't actually say that you didn't provide the URL as bytes. It just said somewhere it wanted bytes and got str (unicode) instead.

I'm guessing you're on Python 3 since I can replicate your exception with your code on Python 3 and not on Python 2. I'm not sure what version of Twisted you're using but I suspect this isn't terribly Twisted-version-specific. Nevertheless, it's a good idea to specify the versions of Python and Twisted in future questions.

The other value you're passing in to request is "GET" and on Python 3, that's a str (unicode). If you encode that (or just make it a bytes literal with b"...") then the exception goes away.

Upvotes: 2

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