That worked, thank you Axel!
In the meantime I also found the class carputils.carpio.igb.IGBFile with which an .igb file can be loaded in Python. The simulation data is then in the IGBFile.data() property, and after resizing using
IGBFile.data().reshape(IGBFile.header()['t'], IGBFile.header()['x'], IGBFile.header()['y'], IGBFile.header()['z'])
the data can be visualized using matplotlib. I hope this might be useful additional information to people with a similar question.