Sometimes, you may have different projects that need different versions of the same packagemodule.

For example, lets say youre developing a web application with the latest version of Django for a customer.

At the same time, you support some old projects that require Django version 1.0.

In that case, you have to change the path that points to Django every time you switch the projects.

It would be very handy to have some tools that allows you to switch from one environment to another without affecting each other.

Virtualenv How To Install Virtualenv

In this article we will show you how to install Virtualenv, and get started.

Everything you install or remove in that environment stays there and other environments are not affected.

Most importantly, you dont pollute the global package directory of your system.

For example, if you want to test an unstable package, virtualenv is the best way to go.

If the unstable module youre testing has some errors in the installationuninstallation process, your system will not be affected by it.

When you are ready to remove the new unstable module, what you need to do is just removing the virtualenv environment you created.

First, lets setup up pip (You may need to become root or use sudo on a Unix machine).

Note that by default in the current version of virtualenv, it uses the --no-site-packages option.

This tells virtualenv to create an empty Python environment for us.

C:Python27 or usrlibpython2.7).

If you need to do this, you can use the --use-site-package argument.

If you list the contents of the current directory (virtualenv) you will see 3 directories.

Also the executables that are installed by some packages will be included in that directory.

The include directory contains the header files of the environment.

As we stated in our example lets install an old version of Django, version 1.0.

With the -p flag you can create environments that use different versions of the Python interpreter.

Lets say for example that you want to create a project with Pythons latest version 3.

To be able to do that, you first need to install the version of Python you want to try on your system.

After that, you need to find the path of the executable of the interpreter.

Install Virtualenv For Mac