How to use Python's "easy_install" on Windows ... it's not so easy!

Question

After installing Python 2.7 on Windows XP, then manually setting the %PATH% to python.exe (why won't the python installer do this?), then installing setuptools 0.6c11 (why doesn't the python installer do this?), then manually setting the %PATH% to easy_install.exe (why doesn't the installer do this?), I finally tried to install a python package with easy_install, but easy_install failed when it couldn't install the pywin32 package, which is a dependency. How can I make easy_install work properly on Windows XP? The failure follows:

C:\>easy_install winpexpect
Searching for winpexpect
Best match: winpexpect 1.4
Processing winpexpect-1.4-py2.7.egg
winpexpect 1.4 is already the active version in easy-install.pth

Using c:\python27\lib\site-packages\winpexpect-1.4-py2.7.egg
Processing dependencies for winpexpect
Searching for pywin32>=214
Reading http://pypi.python.org/simple/pywin32/
Reading http://sf.net/projects/pywin32
Reading http://sourceforge.net/project/showfiles.php?group_id=78018
No local packages or download links found for pywin32>=214
Best match: None
Traceback (most recent call last):
  File "C:\python27\scripts\easy_install-script.py", line 8, in 
    load_entry_point('setuptools==0.6c11', 'console_scripts', 'easy_install')()
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 1712, in main
    with_ei_usage(lambda:
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 1700, in with_ei_usage
    return f()
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 1716, in 
    distclass=DistributionWithoutHelpCommands, **kw
  File "C:\python27\lib\distutils\core.py", line 152, in setup
    dist.run_commands()
  File "C:\python27\lib\distutils\dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "C:\python27\lib\distutils\dist.py", line 972, in run_command
    cmd_obj.run()
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 211, in run
    self.easy_install(spec, not self.no_deps)
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 446, in easy_install
    return self.install_item(spec, dist.location, tmpdir, deps)
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 481, in install_item
    self.process_distribution(spec, dists[0], deps, "Using")
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 519, in process_distribution
    [requirement], self.local_index, self.easy_install
  File "C:\python27\lib\site-packages\pkg_resources.py", line 563, in resolve
    dist = best[req.key] = env.best_match(req, self, installer)
  File "C:\python27\lib\site-packages\pkg_resources.py", line 799, in best_match
    return self.obtain(req, installer) # try and download/install
  File "C:\python27\lib\site-packages\pkg_resources.py", line 811, in obtain
    return installer(requirement)
  File "C:\python27\lib\site-packages\setuptools\command\easy_install.py", line 434, in easy_install
    self.local_index
  File "C:\python27\lib\site-packages\setuptools\package_index.py", line 475, in fetch_distribution
    return dist.clone(location=self.download(dist.location, tmpdir))
AttributeError: 'NoneType' object has no attribute 'clone'

Answer 1

For one thing, it says you already have that module installed. If you need to upgrade it, you should do something like this:

easy_install -U packageName

Of course, easy_install doesn't work very well if the package has some C headers that need to be compiled and you don't have the right version of Visual Studio installed. You might try using pip or distribute instead of easy_install and see if they work better.

Answer 2

I wrote a blog post on how to do this very easily with pictures to follow along, check out here:

http://alphaot.com/2010/10/installing-pythons-easy_install-in-windows-7/

It's on Windows 7, but the steps should work for Windows XP as well.

Answer 3

One problem is that easy_install is set up to download and install .egg files or source distributions (contained within .tgz, .tar, .tar.gz, .tar.bz2, or .zip files). It doesn't know how to deal with the PyWin32 extensions because they are put within a separate installer executable. You will need to download the appropriate PyWin32 installer file (for Python 2.7) and run it yourself. When you run easy_install again (provided you have it installed right, like in Sergio's instructions), you should see that your winpexpect package has been installed correctly.

Since it's Windows and open source we are talking about, it can often be a messy combination of install methods to get things working properly. However, easy_install is still better than hand-editing configuration files, for sure.