Installing packages

To use webapp2 outside of App Engine, you need a package manager to install dependencies in your system – mostly WebOb, and maybe libraries required by the various webapp2_extras modules, if you will use them.

For App Engine, some webapp2_extras modules may require that you install external packages to access specific command line tools (i18n, for example, uses pybabel to extract and compile translation catalogs).

In this tutorial we’ll show how to install a package manager and installer.

Install a distutils library

If you don’t have a distutils library (distribute or setuptools) installed on you system yet, you need to install one. Distribute is recommended, but setuptools will serve as well.

Distribute is “the standard method for working with Python module distributions”. It will manage our package dependencies and upgrades. If you already have one of them, jump to next step. If not, the installation is straighforward:

1. Download the installer and save it anywhere. It is a single file:

2. Execute it from the command line (this will require sudo if you are using Linux or a Mac):

$ python

If you don’t see any error messages, yay, it installed successfully. Let’s move forward. For Windows, check the distribute or setuptools documentation.

Install a package installer

We need a package installer (pip or easy_install) to install and update Python packages. Any will work, but if you don’t have one yet, pip is recommended. Here’s how to install it:

1. Download pip from PyPi:

2. Unpack it and access the unpacked directory using the command line. Then run install on that directory (this will require sudo if you are using Linux or a Mac):

$ python install

That’s it. If you don’t see any error messages, the pip command should now be available in your system.