How do I display the the index of a list element in Python?

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Accessing the index in 'for' loops? 17 answers

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Assuming that you are in Python 3 :

hey = ["lol","hey","water","pepsi","jam"]

for item in hey:
    print(hey.index(item)+1,item)

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

Using <list>.index(<item>) will get you the index of that item.

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.

In Python 3 :

for (i, item) in enumerate(hey, start=1):
    print(i, item)

Or in Python 2 :

for (i, item) in enumerate(hey, start=1):
    print i, item

If you need to know what Python version you are using, type python --version in your command line.

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使用enumerate buit-in方法的start参数：

>>> hey = ["lol", "hey","water","pepsi","jam"]
>>> 
>>> for i, item in enumerate(hey, start=1):
    print(i,item)


1 lol
2 hey
3 water
4 pepsi
5 jam

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简单：

hey = ["lol","hey","water","pepsi","jam"]

for (num,item) in enumerate(hey):
    print(num+1,item)

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