函数式编程filter和map的区别

# b = filter(lambda x:x>5,[1,2,3,4,5,6,7])
# print(list(b))
def filters(x):
    if x > 5:
        return x

b = filter(filters,[1,2,3,4,5,6,7])
print(list(b))#[6, 7]

def maps(x):
    if x > 5:
        return x

b = map(maps,[1,2,3,4,5,6,7])
print(list(b))#[None, None, None, None, None, 6, 7]