Book Image

Learning Python Application Development

By : Ninad Sathaye
Book Image

Learning Python Application Development

By: Ninad Sathaye

Overview of this book

Python is one of the most widely used dynamic programming languages, supported by a rich set of libraries and frameworks that enable rapid development. But fast paced development often comes with its own baggage that could bring down the quality, performance, and extensibility of an application. This book will show you ways to handle such problems and write better Python applications. From the basics of simple command-line applications, develop your skills all the way to designing efficient and advanced Python apps. Guided by a light-hearted fantasy learning theme, overcome the real-world problems of complex Python development with practical solutions. Beginning with a focus on robustness, packaging, and releasing application code, you’ll move on to focus on improving application lifetime by making code extensible, reusable, and readable. Get to grips with Python refactoring, design patterns and best practices. Techniques to identify the bottlenecks and improve performance are covered in a series of chapters devoted to performance, before closing with a look at developing Python GUIs.
Table of Contents (18 chapters)
Learning Python Application Development
Credits
Disclaimers
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Big O notation


In simple terms, the big O or big Oh notation is a way to represent the computational complexity of an algorithm. Here, the O is the letter O, as in order, and not the number zero. The big O indicates an upper bound or the worst-case scenario of the complexity of an algorithm (details to follow in the next section). This concept can be better explained with an example. Let's take a look at the following code:

num = 100 
x = []
for i in range(num): 
    x.append(i)

Let's call this trivial code fragment an algorithm. It is a simple operation that appends a number to the list inside a for loop. Here, num represents the size of the input used by the algorithm. If you increase num, the algorithm will have to do more work inside the for loop. Increase it further, and the poor algorithm will have to do even more work. Thus, the time taken by the algorithm depends on the value of num and can be expressed as a growth function, f(n). Here, n represents the size of the input that corresponds...