python之装饰器
高阶函数：
def func(): print("This is func") def foo(func): print("this is foo") func() return func foo(func) # 将函数 func 作为参数传递给 foo print(foo(func)) # foo 的返回值是 执行结果： this is foo This is func this is foo This is func <function func at 0x000001B6D6A02EA0>
匿名函数：
def foo(): print("this is ", foo) print(foo) # 表示的是函数 foo() # 执行foo函数 foo = lambda x : x * 2 # 匿名函数 print(foo("10")) # 执行的是 lambda 表达式，而不是原来的 foo 函数，因为 foo 被重新定义了
执行结果：
<function foo at 0x000002D11FF4AB70>
this is foo
1010
装饰器：
1 import time 2 3 username = "guoxf" 4 password = "123456" 5 6 def auth(a): 7 print("ahth a:", a) 8 def first(func): 9 print("first func:", func) 10 def second(*args, **kwargs): 11 start_time = time.time() 12 print(*args, **kwargs) 13 user = input("Username:") 14 pwd = input("Password:") 15 if user == username and pwd == password: 16 func(*args, **kwargs) 17 stop_time = time.time() 18 print("run time:%s" % (stop_time - start_time)) 19 else: 20 exit("输入错误，退出程序。。。") 21 22 return second 23 print("this is first", first) 24 25 return first 26 27 28 def test1(): 29 print("welcome to chaina...") 30 31 32 # @auth("local") 33 def test2(username, password): 34 time.sleep(1) 35 print("this is test2...") 36 37 38 @auth("authtication") 39 def test3(): 40 time.sleep(1.5) 41 print("what are you doing...") 42 43 44 45 first1 = auth("local") # first1 指向 auth 函数的返回值first 的函数 46 test2= first1(test2) # test2 指向 first 函数的返回值second 的函数； test2 传给了 func 47 test2("guoxf","123456") # 执行second 函数 48 49 test3()
执行结果：
ahth a: authtication this is first <function auth.<locals>.first at 0x000002093E80AF28> first func: <function test3 at 0x000002093E82F048> ahth a: local this is first <function auth.<locals>.first at 0x000002093E80AF28> first func: <function test2 at 0x000002093E80AEA0> guoxf 123456 Username:guoxf Password:123456 this is test2... run time:140.81427788734436 Username:guoxf Password:1234567 输入错误，退出程序。。。
下图中红框圈中的部分，两者结果相同
