Book Image

Python Fundamentals

By : Ryan Marvin, Mark Ng’ang’a, Amos Omondi
Book Image

Python Fundamentals

By: Ryan Marvin, Mark Ng’ang’a, Amos Omondi

Overview of this book

<p>After a brief history of Python and key differences between Python 2 and Python 3, you'll understand how Python has been used in applications such as YouTube and Google App Engine. As you work with the language, you'll learn about control statements, delve into controlling program flow and gradually work on more structured programs via functions.</p> <p>As you settle into the Python ecosystem, you'll learn about data structures and study ways to correctly store and represent information. By working through specific examples, you'll learn how Python implements object-oriented programming (OOP) concepts of abstraction, encapsulation of data, inheritance, and polymorphism. You'll be given an overview of how imports, modules, and packages work in Python, how you can handle errors to prevent apps from crashing, as well as file manipulation.</p> <p>By the end of this book, you'll have built up an impressive portfolio of projects and armed yourself with the skills you need to tackle Python projects in the real world.</p>
Table of Contents (12 chapters)
Python Fundamentals
Preface

Breaking Out of Loops


When running loops, sometimes, we might want to interrupt or intervene in the execution of the loops before it runs its full course due to an external factor. For instance, when writing a function looping though a list of numbers, you may want to break when a defined condition external to the program flow is met. We will demonstrate this further.

Python provides us with three statements that can be used to achieve this:

  • break

  • continue

  • pass

The break Statement

The break statement allows you to exit a loop based on an external trigger. This means that you can exit the loop based on a condition external to the loop. This statement is usually used in conjunction with a conditional if statement.

The following is an example program that shows the break statement in action:

# Loop over all numbers from 1 to 10
for number in range(1,11):
  # If the number is 4, exit the loop
  if number == 4:
    break

  # Calculate the product of number and 2
  product = number * 2
  # Print out...