Python equivalent to 'which'?

[Sean 'Shaleh' Perry]

On 30-Jul-2002 eg wrote:
> Is their a python equivalent to the bash shell command 'which'?  I
> haven't found it, and 'which' is such a common word that it may be
> lost in the noise in my dejanews searches :(
> 
> I could grab the PATH environment variable and walk all the paths, but
> I'm hoping python has already done it for me!
> Thanks
> Eric
> -- 
> http://mail.python.org/mailman/listinfo/python-list

>>> def which(exe):
...   for d in string.split(os.getenv('PATH'), ':'):
...     name = os.path.join(d, exe)
...     if os.path.isfile(name): return name
...   return None
... 
>>> which('bash')
'/bin/bash'
>>> which('foo')

that's all 'which' does (-: