length argument missing from DataMatrix() package installation on Mac

Hi! Together with a research assistant I am currently putting together a couple Open Sesame Tutorials for thesis students in my lab, as well as anyone else who is interested (shameless self-promotion here: https://kvonholzen.github.io/Tutorials.html). In two of my tutorials, I use DataMatrix to create and control the information sent to experimental loops.

I created the Tutorials on my computer running Windows 10, and my student is working through the tutorials on her computer running a Mac OS. Unfortunately, we haven't gotten very far, because my assistant is unable to create a DataMatrix. When typing in this code:

from datamatrix import DataMatrix

dm = DataMatrix(length=6)

she gets the following error:

I have a feeling that something is wrong with the installation of the DataMatrix package, but trying to upgrade tells us that it is the most recent version.

Here is her system information:

System

• System: Darwin-19.4.0-x86_64-i386-64bit
• Architektur: 64bit

Module and Pakete

• OpenSesame 3.2.8
• Python 2.7.15 |Anaconda, Inc.| (default, Nov 13 2018, 17:07:45) [GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)]
• QProgEdit 4.1.2
• datamatrix [version unknown]
• qdatamatrix 0.1.18
• pseudorandom [not available]
• fileinspector 1.0.2
• QNotifications 2.0.3
• QOpenScienceFramework 1.3.0
• opencv [not available]
• expyriment 0.9.1b2-11-gc100ee8
• IPython 5.5.0
• numpy 1.14.2
• scipy 1.0.1
• PIL/ PILLOW 1.1.7
• psychopy 1.85.3
• pygame 1.9.3
• pygaze 0.6.0a25
• pyglet 1.2.4
• PyQt 5.9.2
• serial 3.4
• markdown 2.6.9
• yaml 3.12

Apologies for posting on her behalf, she is brand new to Open Sesame and Python coding and I feel responsible for solving this problem.

Thank you in advance for any suggestions!

Katie Von Holzen