index notation python code example
Example 1: python array index range
a[start:stop] # items start through stop-1
a[start:] # items start through the rest of the array
a[:stop] # items from the beginning through stop-1
a[:] # a copy of the whole array
Example 2: is : and :: the same in python slice
a[-1] # last item in the array
a[-2:] # last two items in the array
a[:-2] # everything except the last two items