Book Image

Learning Python

By : Fabrizio Romano
Book Image

Learning Python

By: Fabrizio Romano

Overview of this book

Learning Python has a dynamic and varied nature. It reads easily and lays a good foundation for those who are interested in digging deeper. It has a practical and example-oriented approach through which both the introductory and the advanced topics are explained. Starting with the fundamentals of programming and Python, it ends by exploring very different topics, like GUIs, web apps and data science. The book takes you all the way to creating a fully fledged application. The book begins by exploring the essentials of programming, data structures and teaches you how to manipulate them. It then moves on to controlling the flow of a program and writing reusable and error proof code. You will then explore different programming paradigms that will allow you to find the best approach to any situation, and also learn how to perform performance optimization as well as effective debugging. Throughout, the book steers you through the various types of applications, and it concludes with a complete mini website built upon all the concepts that you learned.
Table of Contents (20 chapters)
Learning Python
Credits
About the Author
Acknowledgements
About the Reviewers
www.PacktPub.com
Preface
Index

Conditional programming


Conditional programming, or branching, is something you do every day, every moment. It's about evaluating conditions: if the light is green, then I can cross, if it's raining, then I'm taking the umbrella, and if I'm late for work, then I'll call my manager.

The main tool is the if statement, which comes in different forms and colors, but basically what it does is evaluate an expression and, based on the result, choose which part of the code to execute. As usual, let's see an example:

conditional.1.py

late = True
if late:
    print('I need to call my manager!')

This is possibly the simplest example: when fed to the if statement, late acts as a conditional expression, which is evaluated in a Boolean context (exactly like if we were calling bool(late)). If the result of the evaluation is True, then we enter the body of code immediately after the if statement. Notice that the print instruction is indented: this means it belongs to a scope defined by the if clause. Execution...