Python zip()函数用法实例分析

> help(zip)
Help on built-in function zip in module __builtin__:
zip(...)
  zip(seq1 [, seq2 [...]]) -> [(seq1[0], seq2[0] ...), (...)]

> x=[1,2,3]
> y=[1,2,3]
> z=(1,2,3)
> zip(x,y,z)
[(1, 1, 1), (2, 2, 2), (3, 3, 3)]

> x=(1,2,3,4)
> y=[1,2,3]
> zip(x,y) #传入参数的长度不等，则返回列表的长度和参数中长度最短的对象相同
[(1, 1), (2, 2), (3, 3)]

> x
(1, 2, 3, 4)
> zip(x)
[(1,), (2,), (3,), (4,)]

> zip()
[]

> x=[1,2,3]
> y=['a','b','c']
> z=[4,5,6]
> xyz=zip(x,y,z)
> xyz
[(1, 'a', 4), (2, 'b', 5), (3, 'c', 6)]
> zip(*xyz)
[(1, 2, 3), ('a', 'b', 'c'), (4, 5, 6)]

> x=[5,6,7]
> [x] #[x]生成一个列表的列表，它只有一个元素x
[[5, 6, 7]]
> [x]*3 #[x] * 3生成一个列表的列表，它有3个元素，[x, x, x]
[[5, 6, 7], [5, 6, 7], [5, 6, 7]]
> x
[5, 6, 7]
> zip(*[x]*3) #zip(* [x] * 3)等价于zip(x, x, x)
[(5, 5, 5), (6, 6, 6), (7, 7, 7)]

> name=['song','ping','python']
> age=[26,26,27]
> zip(name,age)
[('song', 26), ('ping', 26), ('python', 27)]
> for n,a in zip(name,age):
...   print n,a
...
song 26
ping 26
python 27