Book Image

Python Fundamentals

By : Ryan Marvin, Mark Nganga, Amos Omondi
Book Image

Python Fundamentals

By: Ryan Marvin, Mark Nganga, Amos Omondi

Overview of this book

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. 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. 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.
Table of Contents (12 chapters)
Python Fundamentals
Preface

while Versus if


The main difference between an if and a while statement is that an if statement gives you the opportunity to branch the execution of code once based on a condition. The code in the if block is only executed once. For instance, if a value is greater than another, an if statement will branch out and execute a computation, and then proceed with the program's flow or exit.

A while statement, however, gives you the opportunity to run a block of code multiple times as long as a condition evaluates to true. This means that a while statement will, for example, execute a computation as long as value A is greater than value B and only proceed with the program flow when A is no longer greater than B.

In this sense, a while statement can be considered a loop. We'll look at looping structures next.