How to get the python.exe location programmatically?

This works in Linux & Windows:

Python 3.x

>>> import sys
>>> print(sys.executable)
C:\path\to\python.exe

Python 2.x

>>> import sys
>>> print sys.executable
/usr/bin/python

I think it depends on how you installed python. Note that you can have multiple installs of python, I do on my machine. However, if you install via an msi of a version of python 2.2 or above, I believe it creates a registry key like so:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\Python.exe

which gives this value on my machine:

C:\Python25\Python.exe

You just read the registry key to get the location.

However, you can install python via an xcopy like model that you can have in an arbitrary place, and you just have to know where it is installed.