Introduction to Python Programming

4.8Chapter summary

Highlights from this chapter include:

• Booleans represent a value of True or False.
• Comparison operators compare values and produce True or False.
• Logical operators take condition operand(s) and produce True or False.
• Operators are evaluated in order according to precedence and associativity.
• Conditions are expressions that evaluate to True or False.
• Decision statements allow different paths of execution (branches) through code based on conditions.
• Decision statements can be nested inside other decision statements.
• Conditional expressions are single-line versions of if-else statements.

At this point, you should be able to write programs that evaluate conditions and execute code statements accordingly with the correct order of operations. The programming practice below ties together most topics presented in the chapter.

Function Description
bool(x)

Converts x to a Boolean value, either True or False.

Operator Description

x == y
(Equality)

Compares the values of x and y and returns True if the values are equal and False otherwise. Ex: 10 == 10 is True.

x != y
(Inequality)

Compares the values of x and y and returns True if the values are inequal and False otherwise. Ex: 7 != 4 is True.

x > y
(Greater than)

Compares the values of x and y and returns True if the x is greater than y and False otherwise. Ex: 9 > 3 is True.

x < y
(Less than)

Compares the values of x and y and returns True if the x is less than y and False otherwise. Ex: 9 < 8 is False.

x >= y
(Greater than or equal)

Compares the values of x and y and returns True if the x is greater than or equal to y and False otherwise. Ex: 2 >= 2 is True.

x <= y
(Less than or equal)

Compares the values of x and y and returns True if the x is less than or equal to y and False otherwise. Ex: 8 <= 7 is False.

x and y
(Logical)

Evaluates the Boolean values of x and y and returns True if both are true. Ex: True and False is False.

x or y
(Logical)

Evaluates the Boolean values of x and y and returns True if either is true. Ex: True or False is True.

not x
(Logical)

Evaluates the Boolean value of x and returns True if the value is false and False if the value is true. Ex: not True is False.

Decision statement Description

if statement

    # Statements before

if condition:
# Body

# Statements after


else statement

    # Statements before

if condition:
# Body
else:
# Body

# Statements after


elif statement

    # Statements before

if condition:
# Body
elif condition:
# Body
else:
# Body

# Statements after


Nested if statement

    # Statements before

if condition:
if condition:
# Body
else:
# Body
else:
if condition:
# Body
else:
# Body

# Statements after

Conditional expression

expression_if_true if condition else expression_if_false

Table 4.5 Chapter 4 reference.

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

• If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
• If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
Citation information

© Mar 15, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.

This book utilizes the OpenStax Python Code Runner. The code runner is developed by Wiley and is All Rights Reserved.