[Python3] Define a decorator to measure the execution time of a function

I felt that it would be possible to measure the execution time of a function just by adding a decorator, so I tried it. (I think it's already in the package)

Implementation example

Since I am using f-string soberly, Python 3.6 or higher is required, but I think that 2.7 will work with some modifications.

Defining a decorator that measures the execution time of a function

import time

def calc_time(message='', parser=None):
    def _calc_time(func):
        import functools

        @functools.wraps(func)
        def wrapper(*args, **kargs):
            start = time.time()
            ret = func(*args, **kargs)
            if parser:
                parsed_message = parser(message, *args, **kargs)
                print(
                    f'end time : {time.time() - start:0.4} sec : {parsed_message}')
            else:
                print(f'end time : {time.time() - start:0.4} sec : {message}')
            return ret
        return wrapper
    return _calc_time

I think there are cases where I want to display a message that uses a function argument, so I am making it possible to pass a function object for message processing.

Example of use

test.py

import time


def message_parser(message, *args, **kargs):
    return f"{message} and {args[0]}"


def calc_time(message='', parser=None):
    def _calc_time(func):
        import functools

        @functools.wraps(func)
        def wrapper(*args, **kargs):
            start = time.time()
            ret = func(*args, **kargs)
            if parser:
                parsed_message = parser(message, *args, **kargs)
                print(
                    f'end time : {time.time() - start:0.4} sec : {parsed_message}')
            else:
                print(f'end time : {time.time() - start:0.4} sec : {message}')
            return ret
        return wrapper
    return _calc_time


@calc_time()
def test1():
    time.sleep(0.2)
    print('call test1')


@calc_time('something message')
def test2():
    time.sleep(0.2)
    print('call test2')


@calc_time('something message', parser=message_parser)
def test3(something_args):
    time.sleep(0.2)
    print('call test3')


@calc_time('something message',
           parser=lambda message, *args, **kargs: f"{message} and {args[0]}")
def test4(something_args):
    time.sleep(0.2)
    print('call test4')

@calc_time('something message',
           parser=lambda message, *args, **kargs: f"{message} and {kargs['something_args']}")
def test5(something_args):
    time.sleep(0.2)
    print('call test4')

@calc_time(parser=lambda message, *args, **kargs: f"{args[0]}")
def test6(something_args):
    time.sleep(0.2)
    print('call test4')

def main():
    test1()
    test2()
    test3('something args')
    test4('something args')
    test5(something_args='something args')
    test6('something args')

if __name__ == '__main__':
    main()

Execution example

$ python test.py
call test1
end time : 0.2001 sec : 
call test2
end time : 0.2 sec : something message
call test3
end time : 0.2001 sec : something message and something args
call test4
end time : 0.2 sec : something message and something args
call test4
end time : 0.2 sec : something message and something args
call test4
end time : 0.2008 sec : something args

reference

About Python Decorators-Qiita [python] Use functools.wrap () with decorator --logging.info (self) [Python: How to make and use various decorators, and the essence | CUBE SUGAR STORAGE](http://momijiame.tumblr.com/post/86112194941/python-%E8%89%B2%E3%80%85%E3% 81% AA% E3% 83% 87% E3% 82% B3% E3% 83% AC% E3% 83% BC% E3% 82% BF% E3% 81% AE% E4% BD% 9C% E3% 82% 8A%E6%96%B9%E3%81%A8%E4%BD%BF%E3%81%84%E6%96%B9%E3%81%9D%E3%81%97%E3%81%A6% E6% 9C% AC% E8% B3% AA)