几个比较重要的内置函数

# 几个重要的内置函数

# 1 zip
l = [1,2,3,4]
l2 = ['a','b','c']
for i in zip(l,l2):
    print(i)

# 2 filter：只筛选不改变原来的值
def is_odd(num):
    return num % 2 == 1

ret = filter(is_odd,[1,2,3,4,5,6,7,8,9])
print(ret)
for i in ret:
    print(i)

# 3 map：只保证元素个数相同
ret = map(abs,[1,-4,6,-8])
print(ret)
for i in ret:
    print(i)

# 4 sort
l = [1,2,3,4]
print(sorted(l))
# l.sort()在原列表直接排序
# sorted新建一个列表