How to properly install Python packages?

Question

I run a Slackware system and I'm trying to run some Python code, but getting a lot of errors such as this one below:

>>> import urllib2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/urllib2.py", line 91, in <module>
    import hashlib
  File "/usr/lib/python2.6/hashlib.py", line 136, in <module>
    md5 = __get_builtin_constructor('md5')
  File "/usr/lib/python2.6/hashlib.py", line 63, in __get_builtin_constructor
    import _md5
ImportError: No module named _md5

urllib2 should be a rather basic lib with Python, how can I get Python working correctly?

Reason being is that urllib2 seems to be a dependancy of praw: https://github.com/praw-dev/praw/issues/135

Trying to install pip to get this installed gives me:

Traceback (most recent call last):
  File "setup.py", line 5, in <module>
    from setuptools import setup
ImportError: No module named setuptools

So I tried installing setuptools:

running install
Traceback (most recent call last):
  File "setup.py", line 94, in <module>
    scripts = scripts,
  File "/usr/lib/python2.6/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/lib/python2.6/distutils/dist.py", line 975, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.6/distutils/dist.py", line 995, in run_command
    cmd_obj.run()
  File "/root/setuptools-0.6c11/setuptools/command/install.py", line 76, in run
    self.do_egg_install()
  File "/root/setuptools-0.6c11/setuptools/command/install.py", line 85, in do_egg_install
    easy_install = self.distribution.get_command_class('easy_install')
  File "/root/setuptools-0.6c11/setuptools/dist.py", line 395, in get_command_class
    self.cmdclass[command] = cmdclass = ep.load()
  File "/root/setuptools-0.6c11/pkg_resources.py", line 1954, in load
    entry = __import__(self.module_name, globals(),globals(), ['__name__'])
  File "/root/setuptools-0.6c11/setuptools/command/easy_install.py", line 21, in <module>
    from setuptools.package_index import PackageIndex, parse_bdist_wininst
  File "/root/setuptools-0.6c11/setuptools/package_index.py", line 2, in <module>
    import sys, os.path, re, urlparse, urllib2, shutil, random, socket, cStringIO
  File "/usr/lib/python2.6/urllib2.py", line 91, in <module>
    import hashlib
  File "/usr/lib/python2.6/hashlib.py", line 136, in <module>
    md5 = __get_builtin_constructor('md5')
  File "/usr/lib/python2.6/hashlib.py", line 63, in __get_builtin_constructor
    import _md5
ImportError: No module named _md5

Answer 1

You can use pip or easy_install to install python modules.

 $ pip install <package-name>

Edit:

I tried installing urllib2 package and it told me that the real name of requirement urllib2 is urllib3. Here is the what it happened:

pradeep@pradeep-laptop:~$ sudo pip install urllib2
Downloading/unpacking urllib2
  Real name of requirement urllib2 is urllib3
  Could not find any downloads that satisfy the requirement urllib2
No distributions at all found for urllib2
Storing complete log in /home/pradeep/.pip/pip.log
pradeep@pradeep-laptop:~$ sudo pip install urllib3
Downloading/unpacking urllib3
  Downloading urllib3-1.5.tar.gz
  Running setup.py egg_info for package urllib3

Installing collected packages: urllib3
  Running setup.py install for urllib3

Successfully installed urllib3
Cleaning up...
pradeep@pradeep-laptop:~$ python
Python 2.7.3 (default, Apr 20 2012, 22:39:59) 
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import urllib3
>>> 

Edit2:

You can install python-pip from source.

$ wget http://pypi.python.org/packages/source/p/pip/pip-0.7.2.tar.gz
$ tar xzf pip-0.7.2.tar.gz
$ cd pip-0.7.2
$ python setup.py install

Answer 2

Pip is the right way to go in order to install your Python modules. Easy_installer is the default python package installer, but pip replaces it, and should normally be preferred, though a few packages will only install with easy_installer.

Where other answers are breaking down, here, is how to install software on a slackware machine. Rather than building new software yourself, you should check out Slackbuilds.org. This repository shares a link to the software source, and a custom build script for Slackware to compile the software and make a Slackware package that can easily be installed/uninstalled/upgraded, and is tracked by Slackware's package management system, installpkg/updatepkg/removepkg. Slackbuilds will also let you know of dependencies on other slackbuilds packages. Please note, slackbuilds assumes a comprehensive Slackware installation, and doesn't tell you any dependencies on the standard slack packages.

Assuming Slack 14.0, you will need: http://slackbuilds.org/repository/14.0/python/pip/ http://slackbuilds.org/repository/14.0/python/distribute/

Finally, please look into slackpkg and sbopkg for more comprehensive automated package management for Slackware. Slackware officially doesn't support slackpkg, or slackbuilds, though they are widely used and well maintained.