python split at index

>>> list1 = ['a','b','c','d','e','f','g','h', 'i', 'j', 'k', 'l']
>>> print list1[:5]
['a', 'b', 'c', 'd', 'e']
>>> print list1[-7:]
['f', 'g', 'h', 'i', 'j', 'k', 'l']
# Note how you can slice either positively or negatively.
# When you use a negative number, it means we slice from right to left.

Here is what the above code is Doing:
1. We create a list called list1.
2. We print the first 5 elements of list1.
3. We print the last 7 elements of list1.