Migrating content out of one blogging or content management system into another is one of those tasks that doesn't usually merit writing a feature-complete, polished migration tool; no two systems are alike, and no two migration scenarios are alike either. Since it's an infrequent process, there's not really incentive for anyone to write or maintain a dedicated Drupal module for doing such migrations (unless perhaps they find themselves doing a whole lot of migrations for clients.)

So, when I went looking for a way to move a bunch of blog posts out of a TypePad blog and into a Drupal site, I was disappointed but not really surprised not to find a ready-made solution.

Rather than rolling my own Drupal module to deal with the problem, I turned to Python and its excellent xmlrpclib library.

Because both TypePad and Drupal implement the MetaWeblog API, I was able to move more than 300 blog entries from one to the other with about 10 lines of Python code. Now, in my case I did not need to worry about preserving comments, multiple authors, or attachments, so I was able to get away with very few headaches... but it would be a good starting place for more complex migrations.

I broke the code up and commented it to make it a bit easier to follow, so it wound up being 37 lines instead of the original 9 or 10... but that's still a lot less code than you'd wind up with if you attacked the problem with a custom Drupal module.

#!/usr/bin/python

import xmlrpclib

# Python script for migrating blog posts out of TypePad and into a Drupal site.
#
# Andy Chase
# The Proof Group LLC
# 2009-07-25
#
# This is a brute force tool, and does not account for mapping TypePad Users 
# to Drupal users or preserving categories and attachments. You'll need to enable 
# the Blog and BlogAPI modules on your Drupal site, and you may want to temporarily 
# set your Drupal site's default input format to 'Full HTML' before doing the import.

#TypePad blog settings
typepadHost = 'http://www.typepad.com/t/api'
typepadBlogId = '1234567890' #Your TypePad blog ID
typepadUser = 'username'
typepadPass = 'password'

#Drupal blog settings
drupalHost = 'http://example.com/xmlrpc.php'
drupalBlogId = 'blog' #Tells BlogAPI to create new nodes with the 'blog' content type
drupalUser = 'username'
drupalPass = 'password'

#Instantiate XML-RPC clients
typepad = xmlrpclib.ServerProxy(typepadHost)
drupal = xmlrpclib.ServerProxy(drupalHost)

#Get posts from TypePad (The last argument is the number of posts you want to retrieve)
posts = typepad.metaWeblog.getRecentPosts(typepadBlogId, typepadUser, typepadPass, 500) 

#Push posts to Drupal
for post in posts:
    drupal.metaWeblog.newPost(drupalBlogId, drupalUser, drupalPass, post, True)

It's worth noting that this technique should work for moving content out of and into any CMS that implements the MetaWeblog API.