context based timer for calculating time

timer.py

from time import perf_counter
from contextlib import contextmanager


@contextmanager
def timer(label: str):
    '''Context Manager for calculating time.

    Note:
        code example is based on Python 3.6
        
    Args:
        label (str): tag/label associated with timer

    Yields:
        tuple(str, float): label associated with calculation 
                            and time calculation
                            
    Examples:
        >>> a = range(1_000_000)
        >>> b = range(1_000_000)
        >>> with timer('array comparison') as comp:
                print(a == b)

        >>> label, time = comp()
        >>> print(f'Total time for {label} {time:.6f} s')

    '''
    start = perf_counter()
    yield lambda: (label, end - start)
    end = perf_counter()