Unnecessary things in python
As a Python user, many things may seem unnecessary in the coding but can be quite helpful.
Type annotation
For example,
def f(x:int, y:int) -> int:
'''Return sum for ints.'''
return x+y
class A:
'''a class for demonstration.'''
def create_A_instance() -> A:
'''Return an instance of A.'''
return A()
https://docs.python.org/3/library/typing.html
Function documentation
Beaware of new features