Pythonizing the examples

A couple of examples in Qt for Python still use C++ syntaxing, idioms and coding styles. This user story relates to identifying and porting those examples to use Python styles and idoms (PEP 8).

Some examples are:

1. Changing cameCase to snake_case for variable names and functions names. Keep in mind that when overriding Qt-methods that are required by a class this cannot be done.
2. Simplify loops: we often see c++ styled for loops and could be replaced by Python loops
3. Usage of context when possible, avoid using f = open(...), and use with open(...) as f: instead.
4. Use pathlib when possible
5. You could optionally adopt the _feature_ module, and rely on a code without setters/getters, and snake_case Qt API. Read more

Helpful Links:

1. Python Styling Guide: https://peps.python.org/pep-0008/
2. Get a list of non PEP8 issues of the code with Flake8 https://flake8.pycqa.org/en/latest/
3. isort for ordering the import statements.
4. Be mindful with using black, even when it's an amazing tool, some of the code we have can get formatted in a strange way, so if you are keen on using it, please do a manual check before submitting the change.