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)
2
Part I: Getting to Know Python
10
PART II: Algorithms and Circuits
14
PART III: Advanced Features and Libraries
19
References
20
Other Books You May Enjoy
Appendices
Appendix C: The Complete UniPoly Class
Appendix D: The Complete Guitar Class Hierarchy
Appendix F: Production Notes

6.8 Nested functions

You can define a function inside another function. We say that the inner function is nested inside the outer.

def f(x, y):
    w = 10
    def g(z):
        return z**3 + w
    return  g(x + y)
f(2, 3)
135

The nested function g on line 3 can see and use w outside its definition but within f.

You cannot call a nested function by name outside its enclosing function.

g(3)
NameError: name 'g' is not defined

To avoid confusion, do not use a parameter name for a nested function that you also use for the containing function. You cannot return from a nested function all the way out of the function in which you defined it. You may code this behavior using an exception via try and except.

You may define more than one nested function, and a nested function may contain additional function definitions within it.

Exercise 6.8

Consider...