How to increment the index itself and not the value stored in index?

Question

I want to increment index "i" by one and not add one to the value stored in "i". How do I do it?

I have tried "i+=1", "i=i+1", "i+1" - none of them works for me.

lst=[1,2,3]
for i in lst:
    print(i+1)

expected result:

2
3
index out of bound error

actual result:

2
3
4

@Austin in java if I try to access an index which is not applicable, i get index out of bound error. I am trying to achive same with python — infoweb, Dec 29 '18 at 17:00
In your code, `i` isn't an index, it's the current value from your array that is getting for-in'd. You want to use a standard for loop. — Drew Reese, Dec 29 '18 at 17:02
for i in list behaves like java's extended for loop , so if you do so it will return the actual value not the index — Sunder R, Dec 29 '18 at 17:02
**you never index anything why would you expect an index error?** — juanpa.arrivillaga, Dec 29 '18 at 17:03
@juanpa.arrivillaga when i try to print(i+1) for i = 2 then I am trying to access i=3, which does not exist in the list because there are only i=0, i=1 and i=2 indexes available. That's why i expect an index out of bound error. — infoweb, Dec 29 '18 at 17:03
`i + 1` doesn't try to access anything, it simply produces a new number the result of adding 1 to `i`. The equivalent code in Java works exactly the same. You never do anything with the list — juanpa.arrivillaga, Dec 29 '18 at 17:07

score 0 · Accepted Answer · answered Dec 29 '18 at 17:07

Try below code, this will give you a range from 0 to 3(not inclusive) then iterate over my_list with the i.

my_list = [1,2,3]
for i in range(0,len(my_list)):
  print(my_list[i+1])

As a result you will be getting the expected result as

2
3
Traceback (most recent call last):
  File "<stdin>", line 2, in <module>
IndexError: list index out of range

list index out of range is equivalent to java index out of bound error

1 Answers1