zip 函数接受任意多个可迭代对象作为参数, 将对象中对应的元素打包成一个 tuple, 然后返回一个可迭代的 zip 对象.
这个可迭代对象可以使用循环的方式列出其元素
若多个可迭代对象的长度不一致, 则所返回的列表与长度最短的可迭代对象相同.
用法 1: 用两个列表生成一个 zip 对象
例 1:
- >>> a1=[1,2,3]
- >>> a2=[4,5,6]
- >>> a3=[7,8,9]
- >>> a4=["a","b","c","d"]
- >>> zip1=zip(a1,a2,a3)
- >>> print(zip1)
- <zip object at 0x7f5a22651c08>
- >>> for i in zip1:
- ... print(i)
- ...
- (1, 4, 7)
- (2, 5, 8)
- (3, 6, 9)
例 2:
- >>> zip2=zip(a1,a2,a4)
- >>> print(zip2)
- <zip object at 0x7f5a22651d48>
- >>> for j in zip2:
- ... print(j)
- ...
- (1, 4, 'a')
- (2, 5, 'b')
- (3, 6, 'c')
例 3:
- >>> zip3=zip(a4)
- >>> print(zip3)
- <zip object at 0x7f5a22651d08>
- >>> for i in zip3:
- ... print(i)
- ...
- ('a',)
- ('b',)
- ('c',)
- ('d',)
例 4:
- >>> zip4=zip(*a4 *3)
- >>>
- >>> print(zip4)
- <zip object at 0x7f5a22651f08>
- >>> for j in zip4:
- ... print(j)
- ...
- ('a', 'b', 'c', 'd', 'a', 'b', 'c', 'd', 'a', 'b', 'c', 'd')
用法 2: 二维矩阵变换 (矩阵的行列互换)
- >>> l1=[[1,2,3],[4,5,6],[7,8,9]]
- >>> print([[j[i] for j in l1] for i in range(len(l1[0])) ])
- [[1, 4, 7], [2, 5, 8], [3, 6, 9]]
- >>> zip(*l1)
- <zip object at 0x7f5a22651f88>
- >>> for i in zip(*l1):
- ... print(i)
- ...
- (1, 4, 7)
- (2, 5, 8)
- (3, 6, 9)
来源: http://www.bubuko.com/infodetail-2567580.html