Editing Defining Django App Dependencies (section)

== requirements.txt ==

It's important to always work in a virtual Python environment when working on Django projects. This way the list of active Python packages that have been installed to support the project will be tracked by `pip`. 

It's possible at any time to list the currently installed Python packages with `pip freeze`. 

To deploy the project's dependencies on another installation, first save the environment in `requirements.txt`:

<syntaxhighlight lang="sh">
$ pip freeze > requirements.txt
</syntaxhighlight>

<p class="alert alert-warning">Creating this file in Windows, even after changing the line endings to Unix-style line endings, caused an error when running `pip install` on the the production Linux server (in `codec.py`).</p>

<p class="alert alert-warning">`psycopg2` will throw an error if PostgreSQL is not installed on the system first.</p>

Lines can be commented out in `requirements.txt` with the pound (`#`) character.

=== Deploying local stand-alone packages ===

See [[Packaging Stand-Alone Django Apps]]

Push the package's distribution to GitHub. 

Add a line to `requirements.txt` to pull the package distribution from GitHub:

<syntaxhighlight lang="text">
-e git://github.com/account_name/package_repo.git#egg=package_name
</syntaxhighlight>

Replacing `account_name`, `package_repo`, and `package_name` in the URL with the appropriate values.

<p class="alert alert-warning">When a package is installed this way, it's necessary to add a directive in `.ebextensions/` to install Git via `yum`.

=== Manually Python package dependencies ===

<syntaxhighlight lang="sh">
$ pip install -r requirements.txt
</syntaxhighlight>

=== Installing Python packages with AWS Elastic Beanstalk ===

`eb create` and `eb deploy` automatically attempts to install all the packages found in `requirements.txt`.