Use idiomatic Python throughout the examples

[thewtex]

To improve example readability and improve familiarity to Pythonistas, we should use idiomatic Python throughout the examples. In the past we had tried to keep the C++ and Python similar, but it is evident that this is less useful than idiomatic Python that people will use in practice.

This means:

• Using snake_case instead of camelCase for variable names
• Not using type declarations, unless required
• Using the Pythonic functional interface to filters when possible
• Not hardcoding types or dimensions when possible

[jhlegarreta]

:+1: to this.

Using snake_case instead of camel_case for variable names

@thewtex Probably?

Using snake_case instead of camelCase for variable names

[thewtex]

Using snake_case instead of camelCase for variable names

Good catch -- corrected.