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Python Python Basics (2015) Python Data Types Specific Index value

Posted by Tyrone Mckellier
Tyrone Mckellier
313 Points

How do I finish this problem ? I don't understand what index -2 means

I got var_one correctly with an index of 5 but when negatives are involved I don't understand how to do it.

index.py 
var_one = [ 1, 2, 3, 4, 5, "t"]
var_two = [ -5, -4, -3, -2, "e"]

1 Answer

Ben Reynolds
Ben Reynolds
35,170 Points
Ben Reynolds
Ben Reynolds
35,170 Points

A negative index value starts at the end of the collection and counts backward, so an index of -2 would be the second to last item.

The confusing part is that an index normally starts counting at 0. But with a negative value, let's say -n, you're targeting the item at the "nth" position from the end.

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Think of it this way - the index still starts at zero, which is the first element. Then move to the left one to get to -1. No more elements to the left? You have to wrap around to the end, then.