In Python how do I slice a list based on an item in the list?

Question

list1 = ['5', '3', '2', '1']
j = '3'

How do I extract from that list from j to the end of the list? In this example giving me:

['3', '2', '1']

when I know j, j is always in the list and the list is always filled with unique values?

Does this answer your question? [Finding the index of an item in a list](https://stackoverflow.com/questions/176918/finding-the-index-of-an-item-in-a-list) — Amir reza Riahi, Apr 14 '22 at 14:34

score 1 · Accepted Answer · answered Apr 14 '22 at 14:39

so since you know the value of j here, we can get the index of j in the list using list1.index(j) now we have to get all the items after j, so we can use this: list1[list1.index(j):]

what this basically does is, it gives all the values from the specified index (our case j) till the end of the list this should give you the desired output!

score 0 · Answer 2 · answered Apr 14 '22 at 14:30

As comments suggest you can get the index number of an item in a list by using index method. Just like this:

>>> list1 = ['5', '3', '2', '1']
>>> list1.index('5')
0
>>> list1.index('1')
3

And then use it to reach the item you want:

>>> i  = list1.index('2')
>>> list1[i]
'2'

In Python how do I slice a list based on an item in the list?

2 Answers2