Introduction to Computing Using Python: An Application Development Focus

CHAPTER 6

Containers and Randomness

6.1 Dictionaries

6.2 Other Built-In Container Types

6.3 Character Encodings and Strings

6.4 Module random

6.5 Case Study: Games of Chance

Chapter Summary

Solutions to Practice Problems

Exercises

Problems

THE FOCUS OF THIS CHAPTER are the other built-in container classes available in Python. While lists are useful general-purpose containers, there are situations when they are awkward or inefficient to use. For this reason, Python provides other built-in container classes.

In a dictionary container, values stored in the container can be indexed using user-specified indexes we call keys. Dictionaries have many different uses, including counting, and they are general-purpose containers just as list containers are. In addition to dictionaries, we also explain when and how to use the tuple and set built-in container classes.

We also come back to strings one more time and look at them as containers of characters. In today's interconnected world, text is created in one place and read in another, and computers have to be able to deal with encoding and decoding characters from different writing systems. We introduce Unicode as the current standard for encoding characters.

In order to introduce a whole new class of problems and applications, including computer games, we end this chapter with a discussion of how to generate “random” numbers. Then, in this chapter's case study, we use randomness to develop a simple blackjack game.

6.1 Dictionaries

We start ...