Python All-in-One For Dummies, 2nd Edition

Chapter 2

Controlling the Action

IN THIS CHAPTER

Deciding with if

Repeating with for

Looping with while

So far in this book we've talked a lot about storing information in computers, mostly in variables that Python and your computer can work with. Having the information in a form that the computer can work with is critical to getting a computer to do anything. Think of this as the “having” part — having some information with which to work.

But now we need to turn our attention to the “doing” part — working with that information to create something useful or entertaining. In this chapter, we cover the most important and most commonly used operations for making the computer do stuff. We start with something that computers do well, do quickly, and do a lot — make decisions.

Main Operators for Controlling the Action

You control what your program (and the computer) does by making decisions, which often involves making comparisons. You use operators, such as those in Table 2-1 to make comparisons. These operators are often referred to as relational operators or comparison operators because by comparing items the computer is determining how two items are related.

TABLE 2-1 Python Comparison ...