Python for Finance, 2nd Edition

Chapter 3. Data Types and Structures

Bad programmers worry about the code. Good programmers worry about data structures and their relationships.

Linus Torvalds

This chapter introduces the basic data types and data structures of Python, and is organized as follows:

“Basic Data Types”

The first section introduces basic data types such as int, float, bool, and str.

“Basic Data Structures”

The second section introduces the fundamental data structures of Python (e.g., list objects) and illustrates, among other things, control structures, functional programming approaches, and anonymous functions.

The aim of this chapter is to provide a general introduction to Python specifics when it comes to data types and structures. The reader equipped with a background from another programing language, say C or Matlab, should be able to easily grasp the differences that Python usage might bring along. The topics and idioms introduced here are important and fundamental for the chapters to come.

The chapter covers the following data types and structures:

Object type	Meaning	Used for
int	Integer value	Natural numbers
float	Floating-point number	Real numbers
bool	Boolean value	Something true or false
str	String object	Character, word, text
tuple	Immutable container	Fixed set of objects, record
list	Mutable container	Changing set of objects
dict	Mutable container	Key-value store
set	Mutable container	Collection of unique objects

Basic Data Types

Python is a dynamically ...