python typing package code example

Example 1: typing python

from collections.abc import Iterable

def zero_all_vars(vars: Iterable[LoggedVar[int]]) -> None:
    for var in vars:
        var.set(0)

Example 2: type declaration python

def greeting(name: str) -> str:
    return 'Hello ' + name

Example 3: python optional type annotation

from custom_module import SomeClass
from typing import Optional

class SubClass:
    a_reference: Optional[SomeClass] # Provides info that a_reference may be 'None'.

    def __init__(self):
        self.a_reference = None

Example 4: python typing module list

"""
typing.Tuple and typing.List are Generic types; this means you can specify what type their contents must be:
"""

def f(points: Tuple[float, float]):
    return map(do_stuff, points)