Improve readability of Python code by following PEP 8

[jarkenau]

We should improve the readability (and consistency) of your Python code by following PEP 8 and integrating it into the existing pre-commit checks. This mainly includes the examples in examples/python/....

[Mark-Niemeyer]

We already use the PEP 8 compliant opinionated formatter Black:

seerep/.pre-commit-config.yaml

Lines 50 to 53 in aba5147

	- repo: https://github.com/psf/black
	rev: 22.12.0
	hooks:
	- id: black

We can adjust its behaviour here:

seerep/pyproject.toml

Lines 30 to 33 in aba5147

	[tool.black]
	line-length = 120
	target-version = ['py38']
	skip-string-normalization = true

[jarkenau]

I think I will update to https://github.com/astral-sh/ruff. It provides a linter, formatter and isort capabilities in one package. Additionally, it looks like the default choice for current projects.