python timer contextmanager

timer.py

from contextlib import contextmanager
import time

@contextmanager
def timer():
    start = time.time()
    yield
    print(f'\N{greek capital letter delta}t \N{rightwards arrow} {time.time() - start:.2f}s')

# usage example
with timer():
    time.sleep(1)
    
# output
# Δt → 1.00s