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pthon: iterate a specific range in a list
原标题:python: iterate a specific range in a list

我要说的是:

listOfStuff =([a,b], [c,d], [e,f], [f,g])

我想做的是,以类似于以下法典的方式通过中间2部分:

for item in listOfStuff(range(2,3))
   print item

最终结果如下:

[c,d]
[e,f]

这项法典目前并不奏效,但我希望你能够理解我正在做些什么。

最佳回答
listOfStuff =([a,b], [c,d], [e,f], [f,g])

for item in listOfStuff[1:3]:
    print item

你们必须听从你们的传说。 <代码>1是你需要的第一个要素,3(实际上为2+1)是你不需要的第一个要素。

清单中的要素从0项计算:

listOfStuff =([a,b], [c,d], [e,f], [f,g])
               0      1      2      3

<代码>[1:3]包括要素1和2。

问题回答

更高效的存储方式是使用islice(),从itertools上删除。 模块:

from itertools import islice

listOfStuff = ([ a , b ], [ c , d ], [ e , f ], [ g , h ])

for item in islice(listOfStuff, 1, 3):
    print(item)

# [ c ,  d ]
# [ e ,  f ]

However, this can be relatively inefficient in terms of performance if the start value of the range is a large value since islice would have to iterate over the first start value-1 items before returning items.

You want to use slicing.

for item in listOfStuff[1:3]:
    print item

采用<代码>ter 建设:

l = [1, 2, 3]
# i is the first item.
i = iter(l)
next(i)
for d in i:
    print(d)




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