Удобный контекстный менеджер для засекания исполнения чего-либо

timer.py

from time import time


class Timer:
    def __init__(self, begin=None, end=None):
        self.begin = begin
        self.end = end

    def __enter__(self):
        self.begin = time()
        return self
    
    def __exit__(self, exc_type, exc_val, exc_tb):
        self.end = time()

    @property
    def t(self):
        if self.end is None:
            return time() - self.begin
        else:
            return self.end - self.begin

    def __str__(self):
        return '{:.2f}'.format(self.t)

    def __repr__(self):
        return 'Timer(begin={}, end={})'.format(self.begin, self.end)


class TimerLog(Timer):
    def __init__(self, log='executed at {t}sec', **kwargs):
        super().__init__(**kwargs)
        self.log = log

    def __exit__(self, exc_type, exc_val, exc_tb):
        super().__exit__(exc_type, exc_val, exc_tb)
        print(self.log.format(t=self.t))