Modern Python Cookbook: 130+ updated recipes for modern Python 3.12 with new techniques and tools. 3 Ed

Cover....1 Copyright....3 Contributors....4 Table of Contents....8 Preface....16 Chapter 1: Numbers, Strings, and Tuples....24 Choosing between float, decimal, and fraction....25 Choosing between true division and floor division....32 String parsing with regular expressions....36 Building complicated strings with f-strings....41 Building complicated strings from lists of strings....46 Using the Unicode characters that aren't on our keyboards....49 Encoding strings – creating ASCII and UTF-8 bytes....52 Decoding bytes – how to get proper characters from some bytes....56 Using tuples of items....59 Using NamedTuples to simplify item access in tuples....63 Chapter 2: Statements and Syntax....68 Writing Python script and module files – syntax basics....70 Writing long lines of code....75 Including descriptions and documentation....80 Writing better docstrings with RST markup....85 Designing complex if...elif chains....90 Saving intermediate results with the := "walrus" operator....96 Avoiding a potential problem with break statements....100 Leveraging exception matching rules....104 Avoiding a potential problem with an except: clause....109 Concealing an exception root cause....111 Managing a context using the with statement....114 Chapter 3: Function Definitions....120 Function parameters and type hints....121 Designing functions with optional parameters....126 Using super flexible keyword parameters....132 Forcing keyword-only arguments with the * separator....137 Defining position-only parameters with the / separator....142 Picking an order for parameters based on partial functions....145 Writing clear documentation strings with RST markup....152 Designing recursive functions around Python's stack limits....157 Writing testable scripts with the script-library switch....162 Chapter 4: Built-In Data Structures Part 1: Lists and Sets....168 Choosing a data structure....169 Building lists – literals, appending, and comprehensions....174 Slicing and dicing a list....180 Shrinking lists – deleting, removing, and popping....186 Writing list-related type hints....192 Reversing a copy of a list....196 Building sets – literals, adding, comprehensions, and operators....200 Shrinking sets – remove(), pop(), and difference....207 Writing set-related type hints....211 Chapter 5: Built-In Data Structures Part 2: Dictionaries....218 Creating dictionaries – inserting and updating....219 Shrinking dictionaries – the pop() method and the del statement....225 Writing dictionary-related type hints....228 Understanding variables, references, and assignment....234 Making shallow and deep copies of objects....238 Avoiding mutable default values for function parameters....244 Chapter 6: User Inputs and Outputs....252 Using the features of the print() function....253 Using input() and getpass() for user input....258 Debugging with f"{value=}" strings....264 Using argparse to get command-line input....266 Using invoke to get command-line input....272 Using cmd to create command-line applications....276 Using the OS environment settings....280 Chapter 7: Basics of Classes and Objects....286 Using a class to encapsulate data and processing....288 Essential type hints for class definitions....292 Designing classes with lots of processing....297 Using typing.NamedTuple for immutable objects....303 Using dataclasses for mutable objects....306 Using frozen dataclasses for immutable objects....312 Optimizing small objects with __slots__....315 Using more sophisticated collections....320 Extending a built-in collection – a list that does statistics....326 Using properties for lazy attributes....330 Creating contexts and context managers....336 Managing multiple contexts with multiple resources....342 Chapter 8: More Advanced Class Design....350 Choosing between inheritance and composition – the "is-a" question....351 Separating concerns via multiple inheritance....358 Leveraging Python's duck typing....365 Managing global and singleton objects....370 Using more complex structures – maps of lists....376 Creating a class that has orderable objects....381 Deleting from a list of complicated objects....387 Chapter 9: Functional Programming Features....394 Writing generator functions with the yield statement....396 Applying transformations to a collection....404 Using stacked generator expressions....409 Picking a subset – three ways to filter....417 Summarizing a collection – how to reduce....422 Combining the map and reduce transformations....428 Implementing ``there exists'' processing....435 Creating a partial function....440 Writing recursive generator functions with the yield from statement....446 Chapter 10: Working with Type Matching and Annotations....454 Designing with type hints....455 Using the built-in type matching functions....463 Using the match statement....467 Handling type conversions....471 Implementing more strict type checks with Pydantic....478 Including run-time valid value checks....485 Chapter 11: Input/Output, Physical Format, and Logical Layout....494 Using pathlib to work with filenames....497 Replacing a file while preserving the previous version....505 Reading delimited files with the CSV module....511 Using dataclasses to simplify working with CSV files....518 Reading complex formats using regular expressions....523 Reading JSON and YAML documents....531 Reading XML documents....539 Reading HTML documents....546 Chapter 12: Graphics and Visualization with Jupyter Lab....556 Starting a Notebook and creating cells with Python code....558 Ingesting data into a notebook....563 Using pyplot to create a scatter plot....569 Using axes directly to create a scatter plot....575 Adding details to markdown cells....581 Including Unit Test Cases in a Notebook....585 Chapter 13: Application Integration: Configuration....590 Finding configuration files....592 Using TOML for configuration files....598 Using Python for configuration files....603 Using a class as a namespace for configuration....608 Designing scripts for composition....614 Using logging for control and audit output....619 Chapter 14: Application Integration: Combination....628 Combining two applications into one....629 Combining many applications using the Command design pattern....637 Managing arguments and configuration in composite applications....643 Wrapping and combining CLI applications....650 Wrapping a program and checking the output....655 Chapter 15: Testing....664 Using docstrings for testing....666 Testing functions that raise exceptions....674 Handling common doctest issues....677 Unit testing with the unittest module....684 Combining unittest and doctest tests....690 Unit testing with the pytest module....695 Combining pytest and doctest tests....700 Testing things that involve dates or times....704 Testing things that involve randomness....709 Mocking external resources....716 Chapter 16: Dependencies and Virtual Environments....726 Creating environments using the built-in venv....729 Installing packages with a requirements.txt file....734 Creating a pyproject.toml file....739 Using pip-tools to manage the requirements.txt file....746 Using Anaconda and the conda tool....750 Using the poetry tool....755 Coping with changes in dependencies....759 Chapter 17: Documentation and Style....766 The bare minimum: a README.rst file....767 Installing Sphinx and creating documentation....772 Using Sphinx autodoc to create the API reference....777 Identifying other CI/CD tools in pyproject.toml....783 Using tox to run comprehensive quality checks....787 Other Books You May Enjoy....796 Packt Page....794 Index....800 Blank Page....819