Platform-specific instructions: macOS

There are multiple ways to install Expyriment. The recommended method requires an active internet connection. If you need to install Expyriment on a computer that has no internet connection (like lab computers), please use the offline method.

Recommended

Using pipx

The most convenient way to install Expyriment is via pipx. This installs Expyriment as an application in an isolated virtual environment. After installation you can use Expyriment through the Command line interface.

1. Install Python 3.13.5

2. To install pipx, run in a terminal:

   python3 -m pip install --user pipx
   

3. To install Expyriment, run in a terminal:

   pipx install expyriment
   pipx ensurepath
   

Using pip

The classical and more flexible way to install Exyriment is via pip. This simply installs Expyriment as a library in a Python environment of your choice. After installation you can use Expyriment like any other Python package.

1. Install Python 3.13.5

2. To create (and activate) a virtual environment, run in a terminal:

   python3 -m venv xpy-env
   source xpy-env/bin/activate
   

3. To install Expyriment, run in a terminal:

   pip install -U pip
   pip install expyriment
   

Offline

If you don’t have an internet connection on the computer you want to install Expyriment on, you can download the necessary packages on a different computer that has, and then transfer them to the target computer and install them there. After installation your can use Expyriment like any other Python package.

On an computer with internet connection (same OS, architecture and Python version!)

1. On the Desktop, create a directory called Expyriment_Installation

2. Download Python 3.13.5 to Expyriment_Installation

3. To download Expyriment and dependencies into Expyriment_Installation, run in a terminal:

   python3 -m pip download -d ~/Desktop/Expyriment_Installation expyriment
   

4. Copy the directory Expyriment_Installation from the Desktop to a portable storage device

On the target computer

1. Copy the directory Expyriment_Installation from the portable storage device to the Desktop

2. Install Expyriment_Installation/python-3.13.5-macos11.pkg

3. To create (and activate) a virtual environment, run in a terminal:

   python3 -m venv xpy-env
   source xpy-env/bin/activate
   

4. To install Expyriment, run in a terminal:

   pip install --no-index --find-links ~/Desktop/Expyriment_Installation expyriment
   

Notes

macOS does not report accurate visual presentation times

After the necessary switch to Pygame 2 that happened with Expyriment 1.0.0, macOS does not seem to be reporting accurate visual presentation times. macOS has a compositor running which cannot be turned off. In theory, fullscreen programmes should be able to bypass it automatically, however, this does not seem to be the case in our experience. While Expyriment on macOS will work perfecly fine for designing and implementing your experiments, we do not recommend to use macOS to run an actual experiment (i.e. test participants)!

Do not start your experiments out of IDLE

If you are using the IDLE editor that comes with the Python installation, be aware that IDLE itself is written in Python. Starting your Expyriment programme out of IDLE (by clicking on “Run” or by pressing F5), might thus lead to improper timing!

We therefore strongly suggest to run Expyriment programmes from the command line when testing participants.