context_timer.py

from datetime import datetime
from time import sleep


class Timer(object):
    """ ActiveRecord Migration-style timer using context management. """
    def __init__(self, name):
        self.name = name
        self.start = datetime.utcnow()

    @property
    def label(self):
        return self.start.strftime("%Y%m%d%H%M%S")

    @property
    def delta(self):
        return round((datetime.utcnow() - self.start).total_seconds(), 4)

    def __enter__(self):        
        print("== {} {} ".format(self.label, self.name).ljust(79, "="))

    def __exit__(self, exc_type, exc_val, exc_tb):
        print(
            "== {} {} ({}s) "
            .format(self.label, self.name, self.delta)
            .ljust(79, "="))
 
with Timer("My Context") as timer:
    print("-- do_something")
    sleep(2)
    print("   -> 2.0000s")

# == 20161025134304 My Context ==================================================
# -- do_something
#    -> 2.0000s
# == 20161025134304 My Context (2.0044s) ========================================