How to find index of second p?

Question

letters=['p','q','r','s','p','u']
print(letters.index('p')
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This will print index of first p , I wanna print index of second p,, how to print it?
https://code.sololearn.com/cfwyDmLIFhQp/?ref=app

Answer 1

You find the index of the first p, and then slice away the first p and everything prior to it. Repeat the index method on the remaining list.

print(letters[letters.index('p')+1:].index('p'))

However, this gives you the index of p within the sliced list. In order to obtain the index of the second p within the original list, add the length of the part of the list which has been sliced away.

print(letters[letters.index('p')+1:].index('p') + letters.index('p')+1)

It's getting a little long, so let's see how we should simplify it.

Let 'p' be any generic object, obj.
Let letters.index(obj)+1 be cutLength.

We can generalize this algorithm as:

https://code.sololearn.com/cqjc3JHXBesm/?ref=app

where occur is the nth occurrence,
list is your list, and obj is the object which index you want to find.

Answer 2

I tried print(lettera.count('p')) but it prints, how many times p occurred in the list

Answer 3

https://code.sololearn.com/cctx5r1B9g3X/?ref=app