匿名函数：

#这段代码

def calc(n):
    return n**n
print(calc(10))

#换成匿名函数

calc = lambda n:n**n
print(calc(10))

函数名 = lambda 参数 ：返回值

 

#参数可以有多个，用逗号隔开 #匿名函数不管逻辑多复杂，只能写一行，且逻辑执行结束后的内容就是返回值

#返回值和正常的函数一样可以是任意数据类型

我们可以看出，匿名函数并不是真的不能有名字。 匿名函数的调用和正常的调用也没有什么分别。 就是 函数名(参数) 就可以了

# def add(x,y):return x+y
# add = lambda x,y:x+y
# print(add(1,2))

# print(max([1,2,3,4,-5],key=abs))

# dic={'k1':10,'k2':100,'k3':30}
# # print(max(dic.values()))
# # print(max(dic))
# print(max(dic,key=lambda k:dic[k]))


# def func(x):
#     return x*x
# ret = map(lambda x:x*x,[1,2,3,4,5,6,7,8])
# print(list(ret))

# def func(num):
#     return num>99 and num<1000
ret = filter(func,[1,4,6,823,67,23])
print(list(ret))


# def func(num):
#     return num>99 and num<1000
ret = filter(lambda num: num>99 and num<1000,[1,4,6,823,67,23])
print(list(ret))


def func(num):
    return num > 10
ret = filter(lambda num : num > 10,[1,4,6,823,67,23])
print(list(ret))

面试题：

# d = lambda p:p*2
# t = lambda p:p*3
# x = 2
# x = d(x)   #4 = d(2)
# x = t(x)   #12 = t(4)
# x = d(x)   #24 = d(12)
# print(x)

#2.现有两元组(('a'),('b')),(('c'),('d')),
# 请使用python中匿名函数生成列表[{'a':'c'},{'b':'d'}]
# t1 = (('a'),('b'))
# t2 = (('c'),('d'))
# t3 = zip(t1,t2)  #[('a','c'),('b','d')]
# print(list(map(lambda t:{t[0]:t[1]},[('a','c'),('b','d')])))

#3.
def multipliers():
    return (lambda x:i*x for i in range(4))
print([m(2) for m in multipliers()])
# i = 0
# m =  lambda x:i*x
# m(2)
# i = 1
# m =  lambda x:i*x
# m(2)