Problems installing lxml on a Mac, it installs but module not found

Question

The code

from lxml import etree 

produces the error

ImportError: No module named lxml 

Running

sudo easy_install lxml

results in

lxml 2.2.7 is already the active version in easy-install.pth 
Removing lxml-2.2.7-py2.5-macosx-10.3-i386.egg from site-packages and rerunning sudo easy_install lxml results in
Adding lxml 2.2.7 to easy-install.pth file
Installed /Library/Python/2.5/site-packages/lxml-2.2.7-py2.5-macosx-10.3-i386.egg
Processing dependencies for lxml
Finished processing dependencies for lxml

And yet I still get No module named lxml

What step am I missing in order to use lxml on my Mac (OSX 10.5)?

Update

python --version reports

Python 2.5.2

and running python produces

Python 2.5.2 (r252:60911, Feb 22 2008, 07:57:53) 
[GCC 4.0.1 (Apple Computer, Inc. build 5363)] on darwin

Answer 1

You appear to be trying to easy_install lxml into the Apple-supplied Python 2.5 for OS X 10.5 but using an egg that was likely built with a python.org Python 2.5. If you have both installed on your system, keep in mind that you need to have a separate easy_install (setuptools or Distribute) for each Python. Apple supplies one in /usr/bin for its Python. Ensuring that you are using the python.org one (check which python), you should follow the installation instructions for setuptools or Distribute to install an easy_install for it. That easy_install will be in the bin directory of the python.org framework: /Library/Frameworks/Python.framework/Versions/2.5//bin. Use that easy_install to install lxml; it should then automatically end up in /Library/Frameworks/Python.framework/Versions/2.5/lib. There is a more detailed discussion of a similar problem here and here.

Answer 2

You have multiple versions of python installed on your computer. lxml is installed for one, and you're invoking the other. There's not enough context to divine any more than that.