Python3.4 Virtual Environments on Windows (仮想環境)

The creation of virtual environments

Your pyvenv is installed by default in C:\Python34\Tools\Scripts. To create virtual environments, if you have the relevant PATH and PATHEXT settings:

C:>py -3.4 -m venv c:\path\to\wherever\you\want\it

or equvalently

C:>C:\Python34\Python C:\Python34\Tools\Scripts\ C:\path\to\wherever\you\want\it

To activate the virtual environment


Install libraries on virtual environments

On windows to install numpy, scipy and matplotlib, it is easier to download installers from

 Python Extension Packages for Windows - Christoph Gohlke

than using pip or easy_install. For example, to install numpy-MLK, download its installer and try
(venv) C:\pip C:\Users\Username\Downloads\numpy-MKL-1.9.1.win32-py3.4.exe

Probably you need install Scipy-stack to use scikit-learn.

When python is uninstalled

When you uninstall python, all files and folders in virtual environments still remain. If you try to use python in virtual environment, you will be said that python34.dll is not found and reinstall it.