python function type signature code example

Example 1: typing generator python

# Iterator
def infinite_stream(start: int) -> Iterator[int]:
    while True:
        yield start
        start += 1

# Generator        
def infinite_stream(start: int) -> Generator[int, None, None]:
    while True:
        yield start
        start += 1

Example 2: 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)