# assuming you were not looking for the number -2
# -2 as an index to an array-like object (as a list) will return
# its second-to-last element
# Here is an example
l = [1,27,34,5,6,7,5,84,289,63,52]
print(l[-2])
>>> 63
# Python 2
>>> 10.0 / 3
3.3333333333333335
>>> 10.0 // 3
3.0