timer.py

# -*- coding: utf-8 -*-
from contextlib import contextmanager
from timeit import default_timer


@contextmanager
def elapsed_timer():
    start = default_timer()
    elapser = lambda: default_timer() - start
    yield lambda: elapser()
    end = default_timer()
    elapser = lambda: end-start

with elapsed_timer() as elapsed:
    print(elapsed())
    import time
    time.sleep(1)
    print(elapsed())