pep8 (https://www.python.org/dev/peps/pep-0008/) is the commonly accepted and widely adopted code style convention for Python.
I used pycodestyle (https://pycodestyle.readthedocs.io/en/latest/) to check for pep8 compatibility.
Especially the mix of tabs and spaces in the Python files makes it hard to work with. I switched to spaces, because that's what
pep8 expects and the majority of Python programmers use.
