How do I extend a python module? (python-twitter)

Question

What are the best practices for extending a python module -- in this case I want to extend python-twitter by adding new methods to the base API class.

I've looked at tweepy, and I like that as well, I just find python-twitter easier to understand and extend with the functionality I want.

I have the methods written already, I'm just trying to figure out the best way to add them into the module, without changing the core.

Answer 1

Don't add them to the module. Subclass the classes you want to extend and use your subclasses in your own module, not changing the original stuff at all.

Answer 2

A few ways.

The easy way:

Don't extend the module, extend the classes.

exttwitter.py

import twitter

class Api(twitter.Api):
    pass 
    # override/add any functions here.

Downside : Every class in twitter must be in exttwitter.py, even if it's just a stub (as above)

A harder (possibly un-pythonic) way:

Import * from python-twitter into a module that you then extend.

For instance :

basemodule.py

 class Ball():
    def __init__(self,a):
        self.a=a
    def __repr__(self):
        return "Ball(%s)" % self.a

def makeBall(a):
    return Ball(a)

def override():
    print "OVERRIDE ONE"

def dontoverride():
    print "THIS WILL BE PRESERVED"

extmodule.py

from basemodule import *
import basemodule

def makeBalls(a,b):
    foo = makeBall(a)
    bar = makeBall(b)
    print foo,bar

def override():
    print "OVERRIDE TWO"

def dontoverride():
    basemodule.dontoverride()
    print "THIS WAS PRESERVED"

runscript.py

import extmodule

#code is in extended module
print extmodule.makeBalls(1,2)
#returns Ball(1) Ball(2)

#code is in base module
print extmodule.makeBall(1)
#returns Ball(1)

#function from extended module overwrites base module
extmodule.override()
#returns OVERRIDE TWO

#function from extended module calls base module first
extmodule.dontoverride()
#returns THIS WILL BE PRESERVED\nTHIS WAS PRESERVED

I'm not sure if the double import in extmodule.py is pythonic - you could remove it, but then you don't handle the usecase of wanting to extend a function that was in the namespace of basemodule.

As far as extended classes, just create a new API(basemodule.API) class to extend the Twitter API module.

Answer 3

May I suggest not to reinvent the Wheel here? I'm building a >6k line Twitter Client for 2 month now, at first I checked python-twitter too, but it's lagging a lot behind the recent API changes,, Development doesn't seem to be that active either, also there was(at least when I last checked) no support for OAuth/xAuth).

So after searching around a bit more I discovered tweepy:
http://github.com/joshthecoder/tweepy

Pros: Active development, OAauth/xAuth and up to date with the API.
Chances are high that what you need is already in there.

So I suggest going with that, it's working for me, the only thing I had to add was xAuth(that got merge back to tweepy :)

Oh an a shameless plug, if you need to parse Tweets and/or format them to HTML use my python version of the twitter-text-* libraries:
http://github.com/BonsaiDen/twitter-text-python

This thing is unittestetd an guaranteed to parse Tweets just like Twitter.com does it.