Additional callback parameters

[bra-fsn]

Hi,

I'm trying to set up a Queue based resolver, running in two threads:

1. a while loop, reading a Queue(), calling channel.gethostbyname
2. the DNS resolver thread, running pycares

To identify the original caller in the callback, I need to pass on additional parameters, but currently it's not possible.

It would be nice to have the following:

def cb(result, error, data):
    print result
    print error
    print data

channel.gethostbyname('google.com', socket.AF_INET, cb, data)

Data should be any type of python object, passed to cb as the third argument.

[saghul]

Hi,

You can do that with a partial object, as follows:

from functools import partial

def cb(data, result, error):
    print data, result, error

channel.gethostbyname('google.com', socket.AF_INET, partial(cb, data))

Note that anything you pass to the partial object will come before the result and error arguments.

Is this a workable solution for you?

[bra-fsn]

Perfectly, thanks!