Centos – Install Python 2.4 or newer on Centos 4.x

The apache process is most likely running as a different user and might be picking up a different system path to your own user.

Perhaps, assuming your apache user is www-data, running the following command will confirm it:

sudo su www-data python -V

Last time I played with different versions of python (at least a couple of revisions back so this may have changed and on Debian so with other distros YMMV), when compiling and installing from source you can do make altinstall instead of make install. This creates just a pythonX.Y binary and does not touch any current python binary. This way you get he right version by running, say, python2.6 (or using #!/usr/bin/python2.6 at the head of a script) but if just python is specified the previous default is used. As the standard libraries are usually separated by version they should not conflict, though you may need to tweak your command and library search paths in some cases and some third party modules might need some alteration to install in the non-default place.