Recalling the 04 functions

Decorator

definition:

Tools for decoration

Without changing the source code and calls the following additional new features

Open Closed Principle:

Extension is open (add new features)

Modify the source code is closed (the changes have been implemented functions)

Version One:

import time
start_time = time.time()
def func():
    time.sleep(2)
    print("asdf")
func()
print(time.time() - start_time)

start_time = time.time()
def foo():
    time.sleep(3)
    print("qwer")
foo()
print(time.time() - start_time)

Edition:

def times(f):
    start_time = time.time()
    f()
    print(time.time() - start_time)

def foo():
    time.sleep(3)
    print("asdf")

s = foo
foo = times
foo(s)

Third Edition (version acquaintance decorator):

def times(f):
    def inner():
        start_time = time.time()
        f()
        print(time.time() - start_time)
    return inner
def foo():
    time.sleep(1)
    print("asdf")
foo = times(foo)
foo()

Fourth Edition (Second Edition decorator):

def wrapper():
    def inner():
        print(1)
    return inner
print(wrapper()())


def wrapper(f):                 
    def inner():                
        f()                     
    return inner                                           
def func():                     
    print("123456")             
func = wrapper(func)            
func()                          

low version

import time
def wrapper(f):
    def inner(*args,**kwargs):
        start_time = time.time()
        f(*args,**kwargs)
        print(time.time() - start_time)
    return inner
def func(*args,**kwargs):
    print(f"这是{args,kwargs}函数")
    time.sleep(2)
func = wrapper(func)
func("alex","wusir")

Premium:

import time
def wrapper(f):
    def inner(*args,**kwargs):
        start_time = time.time()
        f(*args,**kwargs)
        print(time.time() - start_time)
    return inner
@wrapper
def func(*args,**kwargs):
    print(f"这是{args,kwargs}函数")
    time.sleep(2)
@wrapper
def foo(*args,**kwargs):
    print(f"这是{args,kwargs}函数,123456")
    time.sleep(3)
func("alex","ahfe")
foo("alex1","faikewfhn")

Syntactic sugar

Syntactic sugar must be placed just above function is decorative