重要内置函数

filter()

str = ['a','b','c','d']

def fun1(s):
    if s != 'a':
        return s

ret = filter(fun1,str)

print(list(ret))



map():

    str = ['a','b','c','d']

    def fun2(s):
         return s + "alvin"
    ret = map(fun2,str)
    print(list(ret))


reduce()

    from functools import reduce

    def add1(x,y):
        return x + y
    print(reduce(add1,range(1,10))) #reduce()的结果就是一个值


lambda()

    def add(a,b):
        return a+b

    lambda a,b:a + b