Scientific Computing with Python 3

Chapter 2. Variables and Basic Types

In this chapter, we will present the most important and basic types in Python. What is a type? It is a set consisting of data content, its representation, and all possible operations. Later in this book, we will make this definition much more precise, when we introduce the concepts of a class in Chapter 8, Classes.

Variables

Variables are references to Python objects. They are created by assignments, for example:

a = 1 
diameter = 3.
height = 5.
cylinder = [diameter, height] # reference to a list

Variables take names that consist of any combination of capital and small letters, the underscore _ , and digits. A variable name must not start with a digit. Note that variable names are case sensitive. A good naming of ...