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)>>> for i in zip1:... print(i)... (1, 4, 7)(2, 5, 8)(3, 6, 9)
例2:
>>> zip2=zip(a1,a2,a4)>>> print(zip2)>>> for j in zip2:... print(j)... (1, 4, 'a')(2, 5, 'b')(3, 6, 'c')
例3:
>>> zip3=zip(a4)>>> print(zip3)>>> for i in zip3:... print(i)... ('a',)('b',)('c',)('d',)
例4:
>>> zip4=zip(*a4 *3)>>> >>> print(zip4)>>> 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)>>> for i in zip(*l1):... print(i)... (1, 4, 7)(2, 5, 8)(3, 6, 9)