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)
16
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17
Index

Creating dictionaries – inserting and updating

A dictionary is one kind of Python mapping. The built-in type dict class provides a number of common features. There are some common variations on these features defined in the collections module.

As we noted in the Choosing a data structure recipe at the beginning of the previous chapter, we'll use a dictionary when we have a key that we need to map to a given value. For example, we might want to map a single word to a long, complex definition of the word, or perhaps some value to a count of the number of times that value has occurred in a dataset.

A dictionary with keys and integer counts is very common. We'll look at a detailed recipe that shows how to initialize the dictionary and update the counter.

Getting ready

We'll look at an algorithm for locating the various stages in transaction processing. This relies on assigning a unique ID to each request and including that ID with each log record...