Perfomance

import cProfile

def profile(func):
    """Decorator for run function profile"""
    def wrapper(*args, **kwargs):
        profile_filename = func.__name__ + '.prof'
        profiler = cProfile.Profile()
        result = profiler.runcall(func, *args, **kwargs)
        profiler.dump_stats(profile_filename)
        return result
    return wrapper

@profile
def main():
    for i in range(1000000):
        'aaa'.replace('a','a')

if __name__ == '__main__':
    main()
    print('ok')


# read:

import pstats

def main():

    p = pstats.Stats(r"C:\Users\User\Desktop\main.prof")
    p.strip_dirs().sort_stats(-1).print_stats()


if __name__ == '__main__':
    main()