Python for loop - skip to last element

Question

How do we skip to the last element in python?

ITS CLEAR NOW!!!!!!!!!!!!

So for example i have a list

foo = ['hello', 'world','how']

And, I have this loop

for i in foo:
    ----------Codes to skip to last element.--------

therefore, variable 'i' becomes the last element in foo, which is 'how'.

    if i == 'how':
       print 'success!'

And yes, i was wondering if there is any method to do so in a for loop, not outside.

The closest I have found is this:

Python skipping last element in while iterating a list using for loop

Please add in the explanation for your answers on how it works.

Edit: Also, if it's not possible, please explain why(optional).

if you what to skip to the last element, then why you use a `for` loop? why not directyly do something with `foo[-1]` — Ever, Dec 25 '13 at 11:36

Kobi K · Answer 1 · 2013-12-25T10:20:42.333

6

You don't have to run on the entire list:

foo = ['hello', 'world','how']

for i in foo[:-1]:
    ........

You can also identify if it's the last by doing:

foo = ['hello', 'world','how']

for i in foo:
    if i == foo[-1]:
        print "I'm the last.."

For more information about list you can refer Docs

And you have a very good tutorial here

edited Dec 25 '13 at 10:20

answered Dec 25 '13 at 10:15

Kobi K

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No, but is it possible in the for-loop? – Lok Jun Dec 25 '13 at 10:16
I mean inside the loop, not on the loop, replacing my commented lines in the code given in the question. – Lok Jun Dec 25 '13 at 10:17
I want the variable i to skip to the last character IN THE LOOP. – Lok Jun Dec 25 '13 at 10:19
@leonneo there are no characters since you are iterating items of a list! please try to edit your question and give some example so it will be easy to understand. – Kobi K Dec 25 '13 at 10:22

Vb407 · Answer 2 · 2013-12-25T10:30:24.457

2

Another method to skip the last element

>>> for index, item in enumerate(foo):
        if index==(len(foo)-1):
            # last element 
        else:
            # Do something

edited Dec 25 '13 at 10:30

answered Dec 25 '13 at 10:21

Vb407

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Why enumerate? Can you explain? – Lok Jun Dec 25 '13 at 10:23
enumerate will make certain loops a bit clearer. you will get index of the item along with the item in the sequence.As you need to skip the last element I have taken index and compared it with the len of list to skip the last – Vb407 Dec 25 '13 at 10:26

volcano · Answer 3 · 2013-12-25T10:36:52.923

1

My understanding is that you want to check whether you've reached the end of the cycle without break ing out of it. Python has beautiful for...else and while..else constructs for that. The else clause is used when the cycle completes without breaking out So that the skeleton for your code:

for word in foo:
   ... you may break out
else:
    print success

Simple and elegant (and more efficient too)

EDIT: OK, now I get what you want. You may use slicing - as it was suggested, but islice of itertools will do the job better:

from itertools import islice:
for word in islice(foo, len(foo)-1):

edited Dec 25 '13 at 10:36

answered Dec 25 '13 at 10:26

volcano

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What breakout? What do you mean? – Lok Jun Dec 25 '13 at 10:33
In a loop, you may put code _if something: break_ . The meaning is that if condition _something_ evaluates to true, your loop will be interrupted immediately. – volcano Dec 25 '13 at 10:39
That's for everyone to refer to only. I am making sure they can add all they want. Also, you can help edit, because it is unclear from the comments – Lok Jun Dec 25 '13 at 10:41

Python for loop - skip to last element

3 Answers3