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Modern Python Cookbook

You're reading from   Modern Python Cookbook 133 recipes to develop flawless and expressive programs in Python 3.8

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Product type Paperback
Published in Jul 2020
Publisher Packt
ISBN-13 9781800207455
Length 822 pages
Edition 2nd Edition
Languages
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Author (1):
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Steven F. Lott Steven F. Lott
Author Profile Icon Steven F. Lott
Steven F. Lott
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Toc

Table of Contents (18) Chapters Close

Preface 1. Numbers, Strings, and Tuples 2. Statements and Syntax FREE CHAPTER 3. Function Definitions 4. Built-In Data Structures Part 1: Lists and Sets 5. Built-In Data Structures Part 2: Dictionaries 6. User Inputs and Outputs 7. Basics of Classes and Objects 8. More Advanced Class Design 9. Functional Programming Features 10. Input/Output, Physical Format, and Logical Layout 11. Testing 12. Web Services 13. Application Integration: Configuration 14. Application Integration: Combination 15. Statistical Programming and Linear Regression 16. Other Books You May Enjoy
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...

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