Slicing to a file

[Liquid_Ocelot]

Does anyone know how to take user inputs and put that in to the slice method?. I know there are two numbers in the slice method separated by colon. The one on the left will remove elements on the left of the list. The number on the right will remove elements from the end the list.

Something like

sliceline = int(input("How many lines from the start")
    for num in range (sliceline):
          list[sliceline:]

and then the same for the end slicing number

sliceline2 = int(input("How many lines from the start")
    for num in range (sliceline):
          list[:sliceline2]

Hard to explain sorry but yeah im pretty stuck.