Like most programming languages, Python supports a number of ways to control the execution of a program by using control statements. Some of them might already be familiar, while others are unique to Python either in terms of syntax or execution.
In this chapter, we will delve into controlling program flow and start working on building more structured programs. This should also prepare us for learning various kinds of loops later in this chapter. To start us off, we are going to define some terms:
Program flow
Control statement
Program flow describes the way in which statements in code are executed. This also includes the priority given to different elements.
Python uses a simple top-down program flow. This is to say that code is executed in sequence from the top of the file to the very bottom. Each line has to wait until all of the lines that come before it have completed execution before their own execution can begin.
This top-down program flow makes it easy to...