# First-party extensions

Hypothesis has minimal dependencies (just attrs), to maximise compatibility and make installing Hypothesis as easy as possible.

Our integrations with specific packages are therefore provided by `extra` modules that need their individual dependencies installed in order to work. You can install these dependencies using the setuptools extra feature as e.g. `pip install hypothesis[django]`. This will check installation of compatible versions.

You can also just install hypothesis into a project using them, ignore the version constraints, and hope for the best.

In general “Which version is Hypothesis compatible with?” is a hard question to answer and even harder to regularly test. Hypothesis is always tested against the latest compatible version and each package will note the expected compatibility range. If you run into a bug with any of these please specify the dependency version.

There are separate pages for Hypothesis for Django users and Hypothesis for the Scientific Stack.

## hypothesis[pytz]

This module provides pytz timezones.

You can use this strategy to make `hypothesis.strategies.datetimes()` and `hypothesis.strategies.times()` produce timezone-aware values.

`hypothesis.extra.pytz.``timezones`()

  Any timezone in the Olsen database, as a pytz tzinfo object.

  This strategy minimises to UTC, or the smallest possible fixed offset, and is designed for use with `hypothesis.strategies.datetimes()`.