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

9.5 Universality for bit gates

Symbol for a 'nand' gate

Do we need all these gates? Is there some subset of the 1- and 2-bit gates that can generate all the others? Let’s begin with a nand gate and see what we can build from there.

The first new construction is that not x = x nand x. If we feed x to both inputs of nand, we get the same result as not!

Creating 'not' from 'nand' gates

The black dot “●” reuses the bit’s value so we can use it as two inputs.

This circuit shows that if we have nand, we don’t need not as well. Though we may use not in circuits, it is superfluous.

The original set of 1- and 2-bit gates was

not and or xor nand nor xnor .

Since x and y = not (x nand y), the gates we still need are

or xor nand nor xnor .

We can construct or from three nand gates.

Creating 'or' from 'nand' gates

Since x nor y = not (x nor y), our list of required gates...