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

Documenting your code


I'm a big fan of code that doesn't need documentation. When you program correctly, choose the right names and take care of the details, your code should come out as self-explanatory and documentation should not be needed. Sometimes a comment is very useful though, and so is some documentation. You can find the guidelines for documenting Python in PEP257 – Docstring conventions, but I'll show you the basics here.

Python is documented with strings, which are aptly called docstrings. Any object can be documented, and you can use either one-line or multi-line docstrings. One-liners are very simple. They should not provide another signature for the function, but clearly state its purpose.

docstrings.py

def square(n):
    """Return the square of a number n. """
    return n ** 2

def get_username(userid):
    """Return the username of a user given their id. """
    return db.get(user_id=userid).username

Using triple double-quoted strings allows you to expand easily later on...