[Distutils] Single version number

[P.J. Eby]

At 03:58 PM 7/10/2009 +0300, Marius Gedminas wrote:
>What do people use to avoid repeating the version number both in the
>setup.py as well as in application/library code, when the
>application/library wants to know its own version number?
>
>I've seen several options:
>
>   1) put __version__ = '4.2' in yourpackage/__init__.py, have setup.py
>      do from yourpackage import __version__ and pass that to setup()
>
>   2) put __version__ = '4.2' in yourpackage/__init__.py, have setup.py
>      execfile(os.path.join(os.path.dirname(__file__), 'src', 'yourpackage',
>                            '__init__.py'), d), then use d['__version__']
>
>   3) put a file called version.txt in yourpackage/, have setup.py read
>      it, make sure it's included in MANIFEST.in
>
>   4) I don't recall actually ever seeing this one, but it should be
>      possible to use pkg_resources to query the version of yourpackage
>      (downside: if you're running from a source checkout without
>      installing, you won't get the right version number)

You'll get the right version number if you use "setup.py develop" to 
add it to your global sys.path, and/or run "setup.py egg_info" to 
update the version info whenever it changes.

The simplest formula for retrieving the version in that case is 
'pkg_resources.require("Projectname")[0].version'.