Book Image

Dancing with Python

By : Robert S. Sutor
Book Image

Dancing with Python

By: Robert S. Sutor

Overview of this book

Dancing with Python helps you learn Python and quantum computing in a practical way. It will help you explore how to work with numbers, strings, collections, iterators, and files. The book goes beyond functions and classes and teaches you to use Python and Qiskit to create gates and circuits for classical and quantum computing. Learn how quantum extends traditional techniques using the Grover Search Algorithm and the code that implements it. Dive into some advanced and widely used applications of Python and revisit strings with more sophisticated tools, such as regular expressions and basic natural language processing (NLP). The final chapters introduce you to data analysis, visualizations, and supervised and unsupervised machine learning. By the end of the book, you will be proficient in programming the latest and most powerful quantum computers, the Pythonic way.
Table of Contents (29 chapters)
Part I: Getting to Know Python
PART II: Algorithms and Circuits
PART III: Advanced Features and Libraries
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Appendix C: The Complete UniPoly Class
Appendix D: The Complete Guitar Class Hierarchy
Appendix F: Production Notes

2.12 Functions

In this section, we combine many of the techniques in this chapter into examples of functions.

2.12.1 A simple function

This Python code is the definition of an identity function:

def identity(x):
    return x

identity takes one parameter x, does nothing to it, and returns it.

A function definition begins with def followed by the function name. After that, we list zero or more named parameters in parentheses. We end the line with a colon. The body of the function starts on the next line and is indented.

Because of the way I wrote identity, it doesn’t care what the type of x is. It is overloaded to work on anything.

identity("just a string")
'just a string'
identity(["one", 2, 3.0])
['one', 2, 3.0]

The definition of identity defined the parameter x. A parameter...