Python virtualenv

Virtualenv http://pypi.python.org/pypi/virtualenv is very useful.  It creates a new file environment into which you can install python software without screwing up your already installed system python.

To create a virtual environment, if you already have  virtualenv installed, do

• python -m virtualenv myEnv

otherwise,

• download virtualenv-1.5.1.tar.gz
• unpack it: tar xfz virtualenv-*-gz
• create the environment:  python virtualenv-1.5.1/virtualenv.py myEnv
• once the environment (myEnv) has been created,  you can remove the virtualenv-1.5.1 directory.

Example:

curl -s http://pypi.python.org/packages/source/v/virtualenv/virtualenv-1.5.1.tar.gz | tar zxvf -

python virtualenv-1.5.1/virtualenv.py myEnv

Now you can use myEnv/bin/python or myEnv/bin/pip to install packages

(pip can download and install python packages very neatly).