Introduction to Python Programming and Data Structures, 3rd Edition by Pearson

Appendix C

Number Systems

C.1 Introduction

Computers use binary numbers internally, because computers are made naturally to store and process 0s and 1s. The binary number system has two digits, 0 and 1. A number or character is stored as a sequence of 0s and 1s. Each 0 or 1 is called a bit (binary digit).

In our daily life we use decimal numbers. When we write a number such as 20 in a program, it is assumed to be a decimal number. Internally, computer software is used to convert decimal numbers into binary numbers, and vice versa.

We write computer programs using decimal numbers. However, to deal with an operating system, we need to reach down to the “machine level” by using binary numbers. Binary numbers tend to be very long and cumbersome. ...