What is this behaviour of slicing in python?

Question

What happens when we give string[::-1] in python such that the string gets reversed we know that by default the places are acquired by the 0 index and the last index+1 of the string or the -last index and -1 then how on writing above it starts counting from last index whether neither -1 is present at the first place nor the last index so that it starts decreasing 1 from where I can get depth knowledge of working of slicing in python and what does it return like stuff

Answer 1

From the python documentation on slicing sequences like [i:j:k]

The slice of s from i to j with step k is defined as the sequence of items with index x = i + n*k such that 0 <= n < (j-i)/k. In other words, the indices are i, i+k, i+2*k, i+3*k and so on, stopping when j is reached (but never including j). When k is positive, i and j are reduced to len(s) if they are greater. When k is negative, i and j are reduced to len(s) - 1 if they are greater. If i or j are omitted or None, they become “end” values (which end depends on the sign of k). Note, k cannot be zero. If k is None, it is treated like 1.

https://docs.python.org/3/library/stdtypes.html#common-sequence-operations