Psychopy

Psychopy

Development status	Active
Written in	Python
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PsychoPy is an alternative to Presentation, e-Prime and Inquisit. It is a Python library and application that allows presentation of stimuli and collection of data for a wide range of neuroscience, psychology and psychophysics experiments. When used on DCC computers PsychoPy is guaranteed to be millisecond accurate.

Upgrade

Since Python version 2.7 has reached end of life since January first 2020, this version is no longer installed on the PCs in the labs. Standard is now: Python 3.7 64-bits. If you still have scripts written in Python2, the scripts should be upgraded to Python 3. Most changes are probably the print statements. Print statements should always have parentheses: print('some text') Key differences between Python 2 and Python 3 are here: https://sebastianraschka.com/Articles/2014_python_2_3_key_diff.html

Psychopy 2020.2.10 has been installed in the root of the Python3.7 64-bit version. This is also the default version when 'psychopy' is typed from the command prompt. It is also the default that opens when a .py file is double-clicked. It also can be started by clicking the appropriate icon on the desktop. There is also a Psychopy 2020.2.10 installed on Python3.6 32-bits. This version has its own icon on the desktop and should be used when you are using a TOBII Eyetracker.

When your script fails to load in Psychopy, because you need packages that are not installed on our labcomputers, please contact TSG.

On the labcomputer, there is support for Spyder, PyCharm and Psychopy.

Installation for Tobii users

Since Tobii does not support 64-bits and does not support Python higher than version 3.6.8, there is a 32 bits Python version 3.6.8 installed. If you want to use a Tobii Eyetracker and want to install Python and Psychopy yourself, download Python here: Python3.6.8 (Windows) or here: List of downloads for Python3.6.8. Please choose a 32-bit version. Run the installer, choose to add python to the file path (it's an option in the installer).

Download from here: PsychoPyDependenciesPython3.6.8.txt. Open a command prompt (with administrator rights), go to the folder where the downloaded file is and type: pip install -r PsychoPyDependenciesPython3.6.8.txt

This should install everything you need for a basic Psychopy installation. Since packages are updated once in a while, this PsychoPyDependenciesPython3.6.8.txt might get outdated at some time. Please let us know.

Note: in our labs, the 64-bits Python and 64-bits Psychopy are installed as default. The 32-bits Python 3.6.8 and 32-bits Psychopy are installed in a separate virtualenv. If you want to use Python3.6.8 from the command prompt, you first have to type: workon Python36 After that, everything should work from Python3.6.8, including the 32-bits packages.

Installation for other users

We recommend to use a modern 64-bit version of Python. In our labs, we currently have Python 3.7.6 64 bits installed. You can download it here: Python3.7.6 64 bits (Windows) or choose here: Please choose a 64 bit version.. Run the installer and make sure to add Python to the file path (it's an option in the installer).

Download from here: PsychopyRequirements3.7.txt.Open a command prompt (with administrator rights), go to the folder where the downloaded file is and type: pip install -r PsychoPyDependenciesPython3.7.txt

This should install everything you need for a basic Psychopy installation. Since packages are updated once in a while, this PsychoPyDependenciesPython3.7.txt might get outdated at some time. Please let us know.

VirtualEnv

Some of the packages that are installed in the steps above, make it possible to make use of VirtualEnvs. A virtual environment is a Python environment such that the Python interpreter, libraries and scripts installed into it are isolated from those installed in other virtual environments, and (by default) any libraries installed in a “system” Python, i.e., one which is installed as part of your operating system.

If you want to use virtualenvs on your on computer, In System| Advanced system settings | Environment variables, make a new system variable with name WORKON_HOME and value C:\Users\Public\Envs\. And make a new system variable with name: PROJECT_HOME and value C:\Users\Public\Projects. Your virtualenvs will now be stored in C:\Users\Public\Projects and projects in C:\Users\Public\Projects. These are also the places where virtualenvs and projects are stored on the labcomputer.

Open a command window with administrator rights and type:
workon to see a list of existing virtualenvs.
workon <virtualenvname>, where <virtualenvname> is the name of the virtualenv you want to use.
mkvirtualenv <virtualenvname> to create a new and empty virtualenv.
mkvirtualenv -p=37 <virtualenvname> to create a new and empty virtualenv that uses the installed Python3.7.6.
mkvirtualenv -p=36 <virtualenvname> to create a new and empty virtualenv that uses the installed Python3.6.8.
mkvirtualenv -p=37 --system-site-packages <virtualenvname> to create a new virtualenv that uses the installed Python3.7 and its site-packages.
rmvirtualenv <virtualenvname> to remove the virtualenv with name <virtualenvname>.

In our labs, we have th evirtualenvs:
Python36 that contains Python 3.6.8 32-bits, Psychopy and the tobii_research package.
Python37 that contains Python 3.7 64-bits, Psychopy and the pylink package (for use with the Eyelink eyetracker).
and some more virtualenvs that contain packages that would otherwise interfere with Psychopy.

If you need a package that is not installed on our labcomputer, contact TSG, so that we can decide to add it to our standard installation, or to install it in a separate virtualenv. Do not use pip install and install anything in an existing virtualenv. Unless it is your own virtualenv. This might interfere with existing package and might mess up other peoples projects. Instead, make your own virtualenv and install it there. Also, make a backup of your virtualenv, since when the labimage is updated, the newly created virtualenvs will be gone.

Git, Pavlovia

If you want to upload experiments to Pavlovia, you will need to install Git-2.17.1.2-64-bit.exe using these instructions: GitInstall.docx:. Then, in System| Advanced system settings | Environment variables, add the folder where git-daemon.exe is, to the PATH variable. Usually, that folder is named: 'C:\Program Files\Git\mingw64\libexec\git-core'.

The information below is obsolete

Learning PsychoPy

• psychopy tutorial website
• Combining Psychopy and Matplotlib

Templates

Find the presentation Template here Media:TemplatePsychopy2013.zip

Troubleshooting

Version Change to 1.85

If you use audio in psychopy, but you do not choose the back-end yourself (this is the default method), then sound will be played in a different, more reliable way. This may lead to slightly larger but still small latency.We do not expect this to be problematic. If you have any questions about this, come to TSG. Do you use audio in psychopy and choose your own backend with the following line:

prefs.general['audioLib'] = ['pyo']

change this

prefs.general['audioLib'] = ['sounddevice']

This may lead to slightly larger but still small latency. We do not expect this to be problematic.

If you have any questions about this, come to TSG.

Also see: https://github.com/psychopy/psychopy/releases/tag/1.85.0

Version History

For version history and bug fixes please check here: http://www.psychopy.org/changelog.html

Google Mailing list

For various information please click here: https://groups.google.com/forum/#!forum/psychopy-users

GitHub Repository

For requests / bug report / issues click here: https://github.com/psychopy/psychopy