Regions has the following strict requirements:

Region also optionally depends on other packages for some features:

Installing the latest released version

The latest released (stable) version of Regions can be installed either with pip or conda.

Using pip

To install Regions with pip, run:

pip install regions

If you want to install Regions along with all of its optional dependencies, you can instead do:

pip install "regions[all]"

In most cases, this will install a pre-compiled version (called a wheel) of Regions, but if you are using a very recent version of Python or if you are installing Regions on a platform that is not common, Regions will be installed from a source file. In this case you will need a C compiler (e.g., gcc or clang) to be installed for the installation to succeed (see Building from Source prerequisites).

If you get a PermissionError, this means that you do not have the required administrative access to install new packages to your Python installation. In this case you may consider using the --user option to install the package into your home directory. You can read more about how to do this in the pip documentation.

Do not install Regions or other third-party packages using sudo unless you are fully aware of the risks.

Using conda

Regions can be installed with conda if you have installed Anaconda or Miniconda. To install Regions using the conda-forge Anaconda channel, run:

conda install -c conda-forge regions

Building from Source


You will need a compiler suite and the development headers for Python and Numpy in order to build Regions from the source distribution. You do not need to install any other specific build dependencies (such as Cython) since these will be automatically installed into a temporary build environment by pip.

On Linux, using the package manager for your distribution will usually be the easiest route.

On MacOS X you will need the XCode command-line tools, which can be installed using:

xcode-select --install

Follow the onscreen instructions to install the command-line tools required. Note that you do not need to install the full XCode distribution (assuming you are using MacOS X 10.9 or later).

Installing the development version

Regions is being developed on GitHub. The latest development version of the Regions source code can be retrieved using git:

git clone

Then to build and install Regions (with all of its optional dependencies), run:

cd regions
pip install ".[all]"

If you wish to install the package in “editable” mode, instead include the “-e” option:

pip install -e ".[all]"

Alternatively, pip can be used to retrieve, build, and install the latest development version from GitHub:

pip install "git+[all]"

Testing an installed Regions

To test your installed version of Regions, you can run the test suite using the pytest command. Running the test suite requires installing the pytest-astropy (0.11 or later) package.

To run the test suite, use the following command:

pytest --pyargs photutils

Any test failures can be reported to the Regions issue tracker.