How to handle with different pythons in the computer

I'm working wit a Windows 7 machine, and I'm a little confuse about how to handle with the different pythons inside my computer. I have at least four different python's installed in my computer: one in the root path (c:/), one inside the Anaconda distribution, another inside the ArcGis and another in the QuantumGis Distribution.

I'm trying to install the liblas package (libLAS-1.6.0.win32.exe (md5)), but while installing it just sees the ArcGis python, but I would like to use it with Anaconda python...

Any idea about how to handle this? Is it possible to use just one python distribution for those softwares?

Solution

If you are using Anaconda, conda is a better alternative to virtualenv, as it manages conda packages, which are not limited to just Python packages. Create a conda environment like

conda create -n py3k python=3 anaconda

(this will create an environment with Python 3 and all the packages that come with the Anaconda installer).

The activate and deactivate scripts that come with conda will help manage your PATH in the shell.

Typically, to manage things like ArcGis, you want to install those into a conda environment, if possible.