# Plug-ins

Coverage.py’s behavior can be extended with third-party plug-ins. A plug-in is a separately installed Python class that you register in your .coveragerc. Plugins can alter a number of aspects of coverage.py’s behavior, including implementing coverage measurement for non-Python files.

Information about using plug-ins is on this page. To write a plug-in, see Plug-in classes.

New in version 4.0.

## Using plug-ins

To use a coverage.py plug-in, you install it and configure it. For this example, let’s say there’s a Python package called `something` that provides a coverage.py plug-in called `something.plugin`.

1. Install the plug-in’s package as you would any other Python package:

       pip install something

2. Configure coverage.py to use the plug-in. You do this by editing (or creating) your .coveragerc file, as described in Configuration reference. The `plugins` setting indicates your plug-in. It’s a list of importable module names of plug-ins:

       [run]
       plugins =
           something.plugin

3. If the plug-in needs its own configuration, you can add those settings in the .coveragerc file in a section named for the plug-in:

       [something.plugin]
       option1 = True
       option2 = abc.foo

   Check the documentation for the plug-in for details on the options it takes.

4. Run your tests with coverage.py as you usually would. If you get a message like “Plugin file tracers (something.plugin) aren’t supported with PyTracer,” then you don’t have the C extension installed. The C extension is needed for certain plug-ins.

## Available plug-ins

Some coverage.py plug-ins you might find useful:

- Django template coverage.py plug-in: for measuring coverage in Django templates.

- Conditional coverage plug-in: for measuring coverage based on any rules you define! Can exclude different lines of code that are only executed on different platforms, python versions, and with different dependencies installed.

- Mako template coverage plug-in: for measuring coverage in Mako templates. Doesn’t work yet, probably needs some changes in Mako itself.