Introducing Python: Modern Computing in Simple Packages. 3 Ed

Cover....1

Copyright....6

Table of Contents....9

Preface....27

Audience....28

Changes in the Third Edition....28

Outline....28

Python Versions....32

About the Author....32

Conventions Used in This Book....33

Using Code Examples....34

O’Reilly Online Learning....34

How to Contact Us....35

Acknowledgments....35

Part I. Stronghold....37

Chapter 1. Introduction....39

Mysteries....39

Little Python Programs....42

Setup....44

Install Python....45

Upgrade Python....45

Run Python Programs....45

The Python Interactive Interpreter....46

Python Files....46

Built-In Python Features....47

The Python Standard Library....47

Third-Party Python Packages....47

A Bigger Example....47

Review/Preview....50

Chapter 2. Types and Variables....51

A Computer....51

Bits and Bytes....52

Multibyte Types....55

Variables....57

Assign a Value to a Variable....57

Change the Value of a Variable....60

Delete a Variable....61

Name Variables....62

Follow Naming Conventions....63

Python Types....63

Specify Values....64

Objects as Plastic Boxes in Memory....65

Review/Preview....65

Practice....65

Chapter 3. Numbers....67

Booleans....67

Integers....68

Literal Integers....69

Integer Operations....70

Integers and Variables....72

Precedence....74

Bases....75

Type Conversions....77

How Big Is an int?....79

Floats....80

Floats Are Not Exact....82

Fractions....82

Decimals....83

Math Functions....83

Review/Preview....83

Practice....83

Chapter 4. Strings....85

Create with Quotes....86

Create with str()....88

Escape with \....89

Combine with +....90

Duplicate with *....91

Get a Character by [ offset ]....91

Get a Substring with a Slice....92

Get Length with len()....94

Split with split()....95

Combine with join()....95

Substitute with replace()....95

Work with Prefixes and Suffixes....96

Strip with strip()....97

Search and Select....98

Change Case....99

Set Alignment....100

Apply Formatting....100

Old style: %....101

New style: {} and format()....104

Newest Style: f-strings....105

Review/Preview....106

Practice....107

Chapter 5. Bytes and Bytearray....109

Bytes....109

Create with Quotes....110

Create with bytes()....110

Create from a Hex String....111

Decode and Encode Bytes and Strings....112

Convert to a Hex String....112

Get One Byte by [ offset ]....112

Get a Slice....112

Combine with +....113

Repeat with *....113

Bytearray....113

Create with bytearray()....113

Get One Byte by [ offset ]....114

Get Multiple Bytes with a Slice....114

Modify One Byte by [ offset ]....114

Modify Multiple Bytes with replace()....114

Modify Multiple Bytes with a Slice....115

Insert a Byte with insert()....115

Append One Byte with append()....115

Append Multiple Bytes with extend()....115

Combine with +....116

Repeat with *....116

Review/Preview....116

Practice....116

Chapter 6. If and Match....117

Comment with #....117

Continue Lines with \....118

Compare with if, elif, and else....119

What Is True?....122

Do Multiple Comparisons with in....123

New: I Am the Walrus....124

Match....125

Simple Matches....126

Structural Matches....127

Review/Preview....127

Practice....128

Chapter 7. For and While....129

Repeat with while....129

Cancel with break....130

Skip Ahead with continue....130

Check break Use with else....131

Iterate with for and in....131

Cancel with break....132

Skip with continue....132

Check break Use with else....132

Generate Number Sequences with range()....133

Review/Preview....134

Practice....134

Chapter 8. Tuples and Lists....135

Tuples....136

Create with Commas and ()....136

Create with tuple()....138

Get an Item by [ offset ]....138

Combine with +....138

Duplicate with *....138

Compare....138

Iterate with for and in....139

Modify?....139

Lists....140

Create with []....140

Create or Convert with list()....140

Create from a String with split()....141

Get an Item by [ offset ]....141

Get Items with a Slice....142

Add an Item to the End with append()....143

Add an Item by Offset with insert()....143

Duplicate with *....144

Combine with extend() or +....144

Change an Item with [ offset ]....144

Change Items with a Slice....145

Delete an Item by Offset with del....145

Delete an Item by Value with remove()....146

Get an Item by Offset and Delete It with pop()....146

Delete All Items with clear()....147

Find an Item’s Offset by Value with index()....147

Test for a Value with in....147

Count Occurrences of a Value with count()....148

Convert a List to a String with join()....148

Reorder Items with sort() or sorted()....149

Get Length with len()....149

Assign with =....150

Copy with copy(), list(), or a Slice....150

Copy Everything with deepcopy()....151

Compare Lists....152

Iterate with for and in....152

Iterate Multiple Sequences with zip()....153

Iterate Multiple Sequences with zip_longest()....154

Create a List with a Comprehension....155

Create Lists of Lists....157

Tuples Versus Lists....158

There Are No Tuple Comprehensions....158

Review/Preview....159

Practice....159

Chapter 9. Dictionaries and Sets....161

Dictionaries....161

Create with {}....162

Create with dict()....162

Convert with dict()....163

Add or Change an Item by [ key ]....164

Get an Item by [ key ] or with get()....165

Iterate with for and in....166

Get Length with len()....167

Combine/update dicts....167

Delete an Item by Key with del....169

Get an Item by Key and Delete It with pop( key )....169

Delete All Items with clear()....170

Test for a Key with in....170

Assign with =....170

Copy with copy()....171

Copy Everything with deepcopy()....171

Compare Dictionaries....172

Use Dictionary Comprehensions....173

Sets....174

Create with set() or {}....174

Get Length with len()....175

Add an Item with add()....176

Delete an Item with remove()....176

Combine with |....176

Iterate with for and in....176

Test for a Value with in....177

Use Combinations and Operators....177

Create Set Comprehensions....181

Create an Immutable Set with frozenset()....181

Review/Preview....182

Practice....182

Chapter 10. Functions....185

Define a Function with def....185

Call a Function with Parentheses....186

Arguments and Parameters....187

None, Truthiness, and Falsiness....188

Positional Arguments....190

Keyword Arguments....191

Default Parameter Values....191

Pack/Unpack Positional Arguments with *....192

Pack/Unpack Keyword Arguments with **....194

Keyword-Only (*) and Position-Only (/) Arguments....195

Mutable and Immutable Arguments....197

Docstrings....198

Functions Are First-Class Citizens....198

Function Arguments Are Not a Tuple....201

Inner Functions....201

Closures....202

Anonymous Functions: Lambda....203

Generators....204

Generator Functions....204

Generator Comprehensions....206

Decorators....206

Namespaces and Scope....209

Dunder Names....211

Recursion....211

Async Functions, Briefly....213

Exceptions....213

Handle Errors with try and except....214

Use Finally....215

Make Your Own Exceptions....216

Review/Preview....216

Practice....217

Chapter 11. Objects....219

What Are Objects?....219

Simple Objects....220

Define a Class with class....220

Assign Attributes....221

Methods....222

Initialization....222

Inheritance....224

Inherit from a Parent Class....224

Override a Method....225

Add a Method....227

Get Help from Your Parent with super()....227

Use Multiple Inheritance....228

Include Mixins....230

In self Defense....231

Attribute Access....231

Direct Access....231

Getters and Setters....232

Properties for Attribute Access....233

Properties for Computed Values....234

Name Mangling for Privacy....235

Class and Object Attributes....236

Method Types....237

Instance Methods....237

Class Methods....237

Static Methods....238

Duck Typing....238

Magic Methods....241

Aggregation and Composition....244

When to Use Objects or Something Else....244

Named Tuples....245

Dataclasses....247

Attrs....248

Review/Preview....248

Practice....249

Chapter 12. Modules and Packages....251

Modules and the import Statement....251

Import a Module....252

Import a Module with Another Name....254

Import Only What You Want from a Module....254

Packages....254

The Module Search Path....256

Relative and Absolute Imports....257

Namespace Packages....257

Modules Versus Objects....258

Goodies in the Python Standard Library....259

Handle Missing Keys with setdefault() and defaultdict()....259

Count Items with Counter()....261

Order by Key with OrderedDict()....263

Stack + Queue == deque....263

Iterate over Code Structures with itertools....264

Get Random....266

More Batteries: Get Other Python Code....267

Review/Preview....267

Practice....267

Part II. Tools....269

Chapter 13. Development Environment....271

Find Python Code....271

Install Packages....272

Use Pip....272

Install with a Native Package Manager....273

Install from Source....274

Virtual Environments....274

Virtualenv and Venv....275

Pipenv....276

Poetry....276

Conda....276

uv....276

Integrated Development Environments....277

IPython....278

Jupyter Notebook....280

JupyterLab....280

Source Control....280

Mercurial....281

Git....281

Review/Preview....284

Practice....284

Chapter 14. Type Hints and Documentation....285

Type Hints....285

Variable Hints....286

Function Hints....287

Mypy....287

Documentation....288

Comments....289

Docstrings....289

Markup Text Files....289

Review/Preview....289

Practice....290

Chapter 15. Testing....291

Pylint....291

Ruff....293

Unittest....294

Doctest....298

Pytest....299

Examples....300

Fixtures....301

Parametrization....303

Hypothesis....304

Nox....305

Continuous Integration....305

Review/Preview....306

Practice....306

Chapter 16. Debugging....307

Assert....308

Print....309

F-strings....309

Pprint()....310

IceCream....310

Decorators....311

Logging....312

Pdb....315

Breakpoint()....320

Review/Preview....321

Practice....321

Part III. Quests....323

Chapter 17. Text Data....325

Text Strings: Unicode....325

Python Unicode Strings....326

UTF-8....329

Encode....330

Decode....331

HTML Entities....333

Normalization....334

Text Strings: Regular Expressions....335

Find Exact Beginning Match with match()....336

Find First Match with search()....338

Find All Matches with findall()....338

Split at Matches with split()....338

Replace at Matches with sub()....339

Patterns....339

Using Special Characters....339

Using Specifiers....341

Specifying match() Output....343

Review/Preview....344

Practice....344

Chapter 18. Binary Data....345

Convert Binary Data with struct....345

Extraction with Binary Data Tools....348

Convert Bytes/Strings with binascii()....349

Use Bit Operators....349

Review/Preview....350

Practice....350

Chapter 19. Dates and Times....351

Leap Year....352

The datetime Module....353

The time Module....355

Read and Write Dates and Times....357

All the Conversions....361

Alternative Modules....362

Review/Preview....362

Practice....363

Chapter 20. Files....365

File Input and Output....365

Create or Open with open()....366

Write a Text File with print()....367

Write a Text File with write()....367

Read a Text File with read(), readline(), or readlines()....369

Write a Binary File with write()....370

Read a Binary File with read()....371

Close Files Automatically by Using with....371

Change Position with seek()....371

Memory Mapping....373

File Operations....374

Check Existence with exists()....374

Check Type with isfile()....374

Copy with copy()....375

Change Name with rename()....375

Link with link() or symlink()....375

Change Permissions with chmod()....376

Change Ownership with chown()....376

Delete a File with remove()....376

Directory Operations....376

Create with mkdir()....377

Delete with rmdir()....377

List Contents with listdir()....377

Change Current Directory with chdir()....378

List Matching Files with glob()....378

Pathnames....379

Get a Pathname with abspath()....379

Get a symlink Pathname with realpath()....380

Build a Pathname with os.path.join()....380

Use pathlib....380

BytesIO and StringIO....381

File Formats: Determination....383

Review/Preview....383

Practice....383

Chapter 21. Data in Time: Concurrency....385

Programs and Processes....385

Create a Process with subprocess....386

Create a Process with multiprocessing....387

Kill a Process with terminate()....388

Get System Info with os....389

Get Process Info with psutil....389

Command Automation....390

Invoke....390

Other Command Helpers....391

Concurrency....392

Queues....393

Processes....393

Threads....395

The GIL....397

Concurrent.futures....398

Green Threads and gevent....401

Twisted....403

asyncio....405

Coroutines and Event Loops....406

Asyncio Alternatives....408

Async Versus…​....409

Async Frameworks and Servers....410

Redis....411

Beyond Queues....414

Review/Preview....415

Practice....415

Chapter 22. Data in Space: Networks....417

TCP/IP....417

Sockets....418

Scapy....423

Netcat....423

Networking Patterns....424

The Request-Reply Pattern....424

Request-Reply: ZeroMQ....425

Request-Reply: Other Messaging Tools....429

The Publish-Subscribe Pattern....429

Pub-Sub: Redis....429

Pub-Sub: ZeroMQ....431

Pub-Sub: Other Tools....433

Internet Services....433

Domain Name System....433

Python Email Modules....434

Other Protocols....434

Web Services and APIs....435

Data Serialization....435

Serialize with pickle....436

Use Other Serialization Formats....437

Remote Procedure Calls....438

XML-RPC....438

JSON RPC....439

MessagePack RPC....440

zerorpc....441

gRPC....442

Remote Management....443

Big Fat Data....443

Hadoop....443

Spark....444

Disco....444

Dask....444

Clouds....444

Amazon Web Services....446

Google Cloud....446

Microsoft Azure....446

OpenStack....446

Docker....446

Kubernetes....447

Review/Preview....447

Practice....447

Chapter 23. Data in a Box: Persistent Storage....449

Text Files....449

Tabular and Delimited Text Files....450

CSV....450

XML....452

An XML Security Note....454

HTML....455

JSON....455

YAML....458

TOML....460

Tablib....460

Configuration Files....460

Binary Files....461

Padded Binary Files and Memory Mapping....461

Spreadsheets....461

HDF5....462

TileDB....462

Relational Databases....462

SQL....463

DB-API....465

SQLite....465

DuckDB....467

MySQL....467

PostgreSQL....468

SQLAlchemy....468

Other Database Access Packages....474

NoSQL Data Stores....475

The dbm Family....475

Memcached....476

Redis....477

Redis Alternative: Valkey?....484

Document Databases....484

Time-Series Databases....485

Graph Databases....485

Other NoSQL....486

Full-Text Databases....486

Vector Databases....486

Geospatial Databases....487

Review/Preview....487

Practice....487

Chapter 24. The Web....489

Web Basics....490

HTTP Testing....491

Telnet....491

curl....492

HTTPie....493

httpbin....494

Web Clients....494

The Standard Library....494

Requests....496

Other Web Clients....498

Web Servers....500

The Simplest Python Web Server....500

Web Server Gateway Interface....502

ASGI....502

Apache....503

NGINX....504

Other Python Web Servers....504

Web Server Frameworks....505

Bottle....506

Flask....508

Django....512

FastAPI....513

Litestar....513

Database Frameworks....514

Web Services and Automation....515

webbrowser....515

webview....515

Web APIs and REST....516

WebSockets....517

Webhooks....518

Web Frontends....518

htmx....519

FastHTML....519

Crawl and Scrape....520

Scrapy....520

Beautiful Soup....521

Requests-HTML....522

Let’s Watch a Movie....522

Review/Preview....525

Practice....525

Chapter 25. Data Science....527

Standard Python....528

Format Conversions....529

Math....529

Complex Numbers....531

Calculate Accurate Floating Point Values with decimal....532

Perform Rational Arithmetic with fractions....533

Use Packed Sequences with array....533

Statistics....533

Matrix Multiplication....534

NumPy....534

Make an Array with array()....534

Make an Array with arange()....535

Make an Array with zeros(), ones(), or random()....536

Change an Array’s Shape with reshape()....537

Get an Element with []....538

Array Math....539

Linear Algebra....539

SciPy....540

pandas....541

Polars....543

DuckDB....543

Data Visualization....544

Review/Preview....545

Practice....545

Chapter 26. AI....547

It Turns Out…​....548

Expert Systems....548

Perceptrons....548

The Breakthrough....549

Image Recognition: ImageNet and AlexNet....549

Large Language Models....549

The ChatGPT Moment....550

Retrieval Augmented Generation....550

Agents....550

Efficiency....551

Create Models: Python Frameworks....551

Current Models....552

A Million Models: Hugging Face....552

Working Examples With Ollama....553

Install Ollama....553

Choose a Model....554

Choose Another Model....555

Ollama References....557

References....558

Review/Preview....558

Practice....559

Chapter 27. Performance....561

Computer Hardware....561

Measure Timing....563

Profile....567

Algorithms and Data Structures....568

Arrays Versus Lists and Tuples....569

Cache....569

Cython....570

NumPy and SciPy....570

C or Rust Extensions....570

Taichi....571

PyPy....571

Numba....571

Standard Python JIT....572

Mojo....572

Background....573

Design....574

Examples....574

Limitations....575

Conclusion....575

Review/Preview....575

Practice....576

Appendix. Practice Answers....577

2. Types and Variables....577

3. Numbers....578

4. Strings....579

5. Bytes and Bytearray....583

6. If and Match....584

7. For and While....585

8. Tuples and Lists....587

9. Dictionaries and Sets....591

10. Functions....595

11. Objects....597

12. Modules and Packages....601

13. Development Environment....603

14. Type Hints and Documentation....604

15. Testing....604

16. Debugging....607

17. Text Data....607

18. Binary Data....611

19. Dates and Times....612

20. Files....613

21. Data in Time: Concurrency....615

22. Data in Space: Networks....615

23. Data in a Box: Persistent Storage....621

24. The Web....625

25. Data Science....627

26. AI....628

27. Performance....634

Index....637

About the Author....659

Colophon....660

Stuck in a coding conundrum? Whether you're an advanced beginner, an intermediate developer, or a curious newcomer, the complexities of coding can often feel like a labyrinth with no exit. With Python, however, you can start writing real code quickly—but where should you start?

In this updated third edition, Bill Lubanovic acts as your personal guide to Python, offering a clear path through the intricacies and capabilities of this much-beloved coding language, including new chapters on AI models and performance enhancements. Easy to understand and enjoyable to read, this book not only teaches you the core concepts but also dives into practical applications that bridge the gap between learning and doing. By reading it, you will:

• Understand everything from basic data structures to advanced features
• Gain insights into using Python for files, networking, databases, and data science
• Learn testing, debugging, code reuse, and other essential development tips
• Explore how Python can be utilized in business, science, and the arts