Vivienne Reay

What is Slicing?

Slicing extracts part of a string or list.

text = "Hello World"
print(text[0:5])   # Hello

Why start at 0?

Python uses zero-based indexing:

H  e  l  l  o
0  1  2  3  4

Why the end number is not included

Slice numbers are offsets, not character positions.

For "Viv Reay":

name = "Viv Reay"
first = name[0:3]

It includes index 0, 1, 2 and stops before offset 3.

Lists and slicing

items = ["a", "b", "c", "d", "e"]
print(items[1:4])   # ['b', 'c', 'd']

Summary

• Slicing extracts sections
• Start index is included
• End index is excluded
• Works the same on strings and lists