Decorate with a decorator

Decorator

Decorators are like adding some additional behavior to an existing function. For example, you can measure the execution time and output it, or add a message such as "~ ~ function was executed".

sample

This time, I made something to add a message to the output and execution time measurement Code created: https://github.com/KodairaTomonori/Qiita/tree/master/default_module/syntax

Add a message

decoration.py

deco =  '¡+゜+¡･゜･¡+*+¡･★･¡+*+¡･===[ '
deco_end = deco.replace('[', ']')[::-1]
deco_result = [' ∧____∧ Results', '( ｀Д´ )I will output', '(▄︻▇〓┳0035', '/　　 )', '( /￣∪']

def deco_func(func):
    def decoration(*args, **kwargs):
        print(deco + 'start   ' + func.__name__ + deco_end)
        for i in range(len(deco_result) ):
            if i != 2: print(deco_result[i])
            else: print(deco_result[i], func(*args, **kwargs) )
        print(deco + 'end     ' + func.__name__ + deco_end)
    return decoration

@deco_func
def addition(a, b):
    return '{} + {} = {}'.format(a, b, a + b)

if __name__ == '__main__':
    addition(103842, 283746)

output

The decorator is that the deco_func function returns the decoration function created within the function. decoration prints the beginning and end to decorate the output. You can get the function name with func.__name__. Also, by setting (* args, ** kwargs), it is possible to correspond to most functions.

To use it as a decorator, just add @deco_func in front of the function. By doing this, ʻaddition = deco_func (addition) (a, b) `.

measurement of time

timer.py

#usr/bin/python

import time

def timer(func):
    def print_time(*args, **kwargs):
        start = time.time()
        func(*args, **kwargs)
        print(func.__name__ + \
            'The time it took to execute{}Seconds'.format(time.time() - start) )
    return print_time

@timer
def roop_timer(a):
    return roop(a)

def roop(a):
    sum_ = 0
    for i in range(a):
        sum_ += i
    return sum_

if __name__ == '__main__':
    roop_timer(10000)
    timer(roop)(10000)

output

output.txt

roop_The time taken to execute the timer is 0.0008311271667480469 seconds
It took 0 time to execute roop.0008249282836914062 seconds

print_time measures the time and outputs the result. func.__name__ will fetch the function name. If you want to reflect @ timer only partially, you can do the same operation by settingtimer (roop) (10000). It is also possible to create a function dedicated to it, such as roop_timer (it is easier to create this when using two or more).

Summary

You can easily add other functions to a function by adding @decorate_function.