python函数装饰器、推导器、生成器

#装饰器1
def doubler(func):
    def wrapper():
        return func() * 2
    return wrapper
# def get_five():
#     return 5
# doubled = doubler(get_five)
# print(doubled())
@doubler
def get_x():
    return 10
print("装饰器调用结果：")
print(get_x())

#装饰器2
def my_decorator(func):
    def wrapper():
        print("Something is happening before the function is called.")
        func()
        print("Something is happening after the function is called.")
    return wrapper

def say_hello():
    print("Hello!")

say_hello = my_decorator(say_hello)
say_hello()

#--------------函数推导器-----------
print("函数推导器")
fruits = ['Banana', 'Apple', 'Lime']
loud_fruits = [fruit.upper() for fruit in fruits]
print(loud_fruits)

fruits = ['Banana', 'Apple', 'Lime']
print(list(enumerate(fruits)))

def my_function(fname):
  print(fname + " Refsnes")

my_function("Emil")
my_function("Tobias")
my_function("Linus")

#函数生成器
def my_range(n):
    i = 0
    while i < n+8:
        yield i*i
        i +=1
for x in my_range(5):
    print(x)    

输出的结果：

0
1
4
9
16
25
36
49
64
81
100
121
144