python-装饰（高阶函数）

def bar():
    print("in the bar")
def  test1(func):
    print("in the test1")
    print(func)
    func()   #func=bar    func()=bar()
test1(bar)


打印结果
---------------------------------

in the test1
<function bar at 0x000001DA445500D0>
in the bar

#实现bar的运行时间的高阶函数
import time
def bar():
    time.sleep(3)
    print("in the bar")
def  test1(func):
    star_time=time.time()
    func()  #bar()
    stop_time=time.time()
    print("the func run time is %s"%(stop_time-star_time))
test1(bar)


打印结果
-----------------------------------
in the bar
the func run time is 3.0002150535583496

import time

def bar():
    time.sleep(3)
    print("int the bar")
def test2(func):
    print(func)
    return func
print(test2(bar))

t=test2(bar)
bar=test2(bar)
t()  #t()=bar()
print(t)

bar=test2(bar)  #覆盖原来的bar
bar()       #不修改原来的调用方式

打印结果
——————————————————————————
<function bar at 0x00000224596500D0>
<function bar at 0x00000224596500D0>
<function bar at 0x00000224596500D0>
<function bar at 0x00000224596500D0>
int the bar
<function bar at 0x00000224596500D0>
<function bar at 0x00000224596500D0>
int the bar