如何在Python中显示列表元素的索引? [英] How do I display the the index of a list element in Python?
问题描述
我有家庭作业.我有以下代码
I have a homework assignment. I've got the following code
hey = ["lol", "hey","water","pepsi","jam"]
for item in hey:
print(item)
我是否在列表中显示项目之前的位置,像这样:
Do I display the position in the list before the item, like this:
1 lol
2 hey
3 water
4 pepsi
5 jam
推荐答案
假定您在Python 3
中:
hey = ["lol","hey","water","pepsi","jam"]
for item in hey:
print(hey.index(item)+1,item)
如果您在Python 2
中,请仅用print
语句替换print()
:
If you are in Python 2
, replace the print()
with just the print
statement:
hey = ["hey","water","pepsi","jam"]
for item in hey:
print hey.index(item)+1,item
使用<list>.index(<item>)
将获得该项目的索引.
Using <list>.index(<item>)
will get you the index of that item.
但是,正如已经提到的那样,这是低效的(因为它会在每次迭代中进行查找),并且如果存在重复项将无法正常工作.更好的方法是使用enumerate
,因为它可以防止这两个问题.可以按照以下步骤进行.
However, as has been mentioned, this is inefficient (as it does a lookup each iteration) and will not work if there are duplicates. The better method is to use enumerate
, as it prevents both of these issues. That would be done as follows.
在Python 3
中:
for (i, item) in enumerate(hey, start=1):
print(i, item)
或在Python 2
中:
for (i, item) in enumerate(hey, start=1):
print i, item
如果您需要了解所使用的Python版本,请在命令行中输入python --version
.
If you need to know what Python version you are using, type python --version
in your command line.
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