Trace String Expressions

Introduction

This lesson continues the Strings section of PCAP-31-03, which carries 18% of the score and 8 of the 40 items. It covers objective 3.2 (operations on strings: indexing, slicing, immutability, iteration, concatenation, repetition, comparison and the in / not in operators) and prepares objective 3.3, where the string methods are used. The previous lesson explained that a Python str is a sequence of code points. This lesson shows what you can do with that sequence and, above all, how to trace an expression by hand and predict its exact output.