Book Image

Modern Python Cookbook - Second Edition

By : Steven F. Lott
Book Image

Modern Python Cookbook - Second Edition

By: Steven F. Lott

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great language that can power your applications and provide great speed, safety, and scalability. It can be used for simple scripting or sophisticated web applications. By exposing Python as a series of simple recipes, this book gives you insight into specific language features in a particular context. Having a tangible context helps make the language or a given standard library feature easier to understand. This book comes with 133 recipes on the latest version of Python 3.8. The recipes will benefit everyone, from beginners just starting out with Python to experts. You'll not only learn Python programming concepts but also how to build complex applications. The recipes will touch upon all necessary Python concepts related to data structures, object oriented programming, functional programming, and statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively take advantage of it. By the end of this Python book, you will be equipped with knowledge of testing, web services, configuration, and application integration tips and tricks. You will be armed with the knowledge of how to create applications with flexible logging, powerful configuration, command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
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Implementing "there exists" processing

The processing patterns we've been looking at can all be summarized with the universal quantifier, , meaning for all. It's been an implicit part of all of the processing definitions:

  • Map: For all items in the source, , apply the map function, . We can change notation to have an explicit use of the universal quantifier: .
  • Filter: For all items in the source, pass those for which the filter function is true. Here, also, we've used the universal quantifier to make this explicit: .
  • Reduce: For all items in the source, use the given operator and base value to compute a summary. The universal quantification is implicit in the definition of operators like .

There are also cases where we are only interested in locating a single item. We often describe these cases as a search to show there exists at least one item where a condition is true. This can be called the existential quantifier, ,...