Book Image

Secret Recipes of the Python Ninja

Book Image

Secret Recipes of the Python Ninja

Overview of this book

This book covers the unexplored secrets of Python, delve into its depths, and uncover its mysteries. You’ll unearth secrets related to the implementation of the standard library, by looking at how modules actually work. You’ll understand the implementation of collections, decimals, and fraction modules. If you haven’t used decorators, coroutines, and generator functions much before, as you make your way through the recipes, you’ll learn what you’ve been missing out on. We’ll cover internal special methods in detail, so you understand what they are and how they can be used to improve the engineering decisions you make. Next, you’ll explore the CPython interpreter, which is a treasure trove of secret hacks that not many programmers are aware of. We’ll take you through the depths of the PyPy project, where you’ll come across several exciting ways that you can improve speed and concurrency. Finally, we’ll take time to explore the PEPs of the latest versions to discover some interesting hacks.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Foreword
Contributors
Preface
Index

Using the secrets module


This module, while not part of the math set, is important because it makes random numbers that are cryptographically secure. Thus, we will look at how this module differs from the random module.

How to do it...

  • SystemRandom class is the same as the random.SystemRandom class, that is, it provides random numbers and uses the best quality random seeding sources of the system.
  • choice(sequence) method also works just like the random.choice() method.
  • randbelow(n) function returns a random integer in the range [0, n).
  • randbits(k) method returns an integer with k random bits.
  • token_bytes([nbytes=None]) function returns a random byte string. If nbytes is not provided, a reasonable default is used; if provided, the returned string contains that many bytes.
  • token_hex([nbytes=None]) function returns a random text string in hex. The bytes used in the string are converted to two hex digits each.
  • token_urlsafe([nbytes=None]) function returns a random, URL-safe text string of random bytes...