For user-based and certificate-based authentication, do I want to use urllib, urllib2, or curl?

Question

A few months ago, I hastily put together a Python program that hit my company's web services API. It worked in three different modes:

1) HTTP with no authentication
2) HTTP with user-name and password authentication
3) HTTPS with client certificate authentication

I got 1) to work with urllib, but ran into problems with 2) and 3). Instead of figuring it out, I ended up calculating the proper command-line parameters to curl, and executing it via os.system().

Now I get to re-write this program with the benefit of experience, and I'm not sure if I should use urllib, urllib2, or just stick with curl.

The urllib documentation mentions:

When performing basic authentication, a FancyURLopener instance 
calls its prompt_user_passwd() method. The default implementation 
asks the users for the required     information on the controlling 
terminal. A subclass may override this method to support 
more appropriate behavior if needed.

It also mentions the **x509 argument to urllib.URLopener():

Additional keyword parameters, collected in x509, may be used for 
authentication of the client when using the https: scheme. The 
keywords key_file and cert_file are supported to provide an SSL 
key and certificate; both are needed to support client 
authentication.

But urllib2 is one greater than urllib, so naturally I want to use it instead. The urllib2 documentation is full of information about authentication handlers that seem to be designed for 2) above, but makes no mention whatsoever of client certificates.

My question: do I want to use urllib, because it appears to support everything I need to achieve? Or should I just stick with curl?

Thanks.

Edit: Maybe my question isn't specific enough, so here's another shot. Can I achieve what I want to do with urllib? Or with urllib2? Or am I forced to use curl out of necessity?

Answer 1

I choose to use a python module rather than running Unix commands ; unless i don't have a choice

I call it abstraction like that my script or app work every where and don't depend on the hosted OS, even if i know for sure that my script will run only on one specify OS

Answer 2

I believe that mechanize is the module you need.

EDIT: mechanize objects have this method for authentication: add_password(self, url, user, password, realm=None)