Cannot install python packages from source-code

Question

I need to install PIL (python imaging library) on my Ubunto10.4-32bit (EDIT:64bit) machine on my python2.5.4-32bit. This question is also relevant to any other source package I guess (among those that I need are RPyC,psyco and numpy).

I downloaded the source-code since I can't find any neat package to do the job and did a
sudo python2.5 setup.py install.
output:

Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
  File "setup.py", line 9, in <module>
    import glob, os, re, struct, string, sys
  File "/usr/lib/python2.5/struct.py", line 30, in <module>
    from _struct import Struct, error
ImportError: No module named _struct

but

echo $PYTHONHOME
/usr

Well, in the file struct.py theres the line from _struct import Struct, error This is part of the python source code itself so I really wonder whats wrong with the python installation, since the code fails to import the module.
I installed py2.5.4 by doing:

./configure --prefix=/usr
make altinstall 

(using make altinstall since I need py26 as default python interpreter)

EDIT: This issue might have risen from mistakenly using a 64bit platform :) and 32bit python2.5 . So anyhow problem solved by reducing unnecessary complexities - switching to 32bit machine and porting app to python 2.6.

Answer 1

In short:

Try using the Ubuntu repository first. If the package isn't there, use easy_install. If all fails, download the package directly to your source folder.

Ubuntu repository (the apt-get approach)

Ubuntu (10.04 and newer) has most mainstream packages are available with apt-get. The naming convention is python-NAME, e.g. python-imaging or python-scipy.

This is the best way to go, since the native package manager will handle any dependencies and updates issues.

Run apt-cache search python | grep "^python-" | less to see a list of packages available for your system (I have over 1,200 in my 10.04 machine).

Setuptools

For packages that are not part of the Ubuntu repository, you can use the python easy-install tool. First, install the setup tool:

sudo apt-get install python-setuptools

And you can install any Python package, e.g. colorworld, using easy-install:

sudo easy_install colorworld

This gives you some degree of protection (e.g., handles dependencies) but updates are generally manual, and it's a real pain to reinstall all these packages in a new computer.

Manual download

You can always download the source code to some directory and add it to your PYTHONPATH. It's the best approach when you just need to evaluate a package or apply some quick-and-dirty solution.