FastAPI: Modern Python Web Development

Cover....1

Copyright....3

Table of Contents....6

Preface....14

Conventions Used in This Book....15

Using Code Examples....16

O’Reilly Online Learning....16

How to Contact Us....17

Acknowledgments....17

Part I. What’s New?....18

Chapter 1. The Modern Web....20

Preview....20

Services and APIs....21

Kinds of APIs....21

HTTP....22

REST(ful)....22

JSON and API Data Formats....24

JSON:API....24

GraphQL....25

Concurrency....25

Layers....26

Data....29

Review....30

Chapter 2. Modern Python....32

Preview....32

Tools....32

Getting Started....33

Python Itself....34

Package Management....34

Virtual Environments....34

Poetry....35

Source Formatting....36

Testing....36

Source Control and Continuous Integration....36

Web Tools....36

APIs and Services....37

Variables Are Names....37

Type Hints....38

Data Structures....38

Web Frameworks....38

Django....39

Flask....39

FastAPI....39

Review....40

Part II. A FastAPI Tour....42

Chapter 3. FastAPI Tour....44

Preview....44

What Is FastAPI?....44

A FastAPI Application....45

HTTP Requests....49

URL Path....50

Query Parameters....51

Body....53

HTTP Header....54

Multiple Request Data....55

Which Method Is Best?....56

HTTP Responses....56

Status Code....56

Headers....57

Response Types....57

Type Conversion....58

Model Types and response_model....59

Automated Documentation....60

Complex Data....64

Review....64

Chapter 4. Async, Concurrency, and Starlette Tour....66

Preview....66

Starlette....66

Types of Concurrency....67

Distributed and Parallel Computing....67

Operating System Processes....67

Operating System Threads....68

Green Threads....68

Callbacks....68

Python Generators....69

Python async, await, and asyncio....70

FastAPI and Async....72

Using Starlette Directly....74

Interlude: Cleaning the Clue House....74

Review....76

Chapter 5. Pydantic, Type Hints, and Models Tour....78

Preview....78

Type Hinting....78

Data Grouping....81

Alternatives....85

A Simple Example....86

Validate Types....89

Validate Values....90

Review....92

Chapter 6. Dependencies....94

Preview....94

What’s a Dependency?....94

Problems with Dependencies....95

Dependency Injection....95

FastAPI Dependencies....95

Writing a Dependency....96

Dependency Scope....97

Single Path....97

Multiple Paths....98

Global....98

Review....99

Chapter 7. Framework Comparisons....100

Preview....100

Flask....100

Path....101

Query Parameter....102

Body....102

Header....103

Django....103

Other Web Framework Features....104

Databases....105

Recommendations....105

Other Python Web Frameworks....105

Review....106

Part III. Making a Website....108

Chapter 8. Web Layer....110

Preview....110

Interlude: Top-Down, Bottom-Up, Middle-Out?....111

RESTful API Design....112

File and Directory Site Layout....114

The First Website Code....115

Requests....117

Multiple Routers....119

Build the Web Layer....120

Define Data Models....120

Stub and Fake Data....121

Create Common Functions Through the Stack....121

Create Fake Data....121

Test!....126

Using the FastAPI Automated Test Forms....127

Talking to the Service and Data Layers....129

Pagination and Sorting....130

Review....131

Chapter 9. Service Layer....132

Preview....132

Defining a Service....132

Layout....133

Protection....133

Functions....133

Test!....135

Other Service-Level Stuff....137

Logging....137

Metrics, Monitoring, Observability....137

Tracing....137

Other....138

Review....138

Chapter 10. Data Layer....140

Preview....140

DB-API....140

SQLite....142

Layout....144

Making It Work....144

Test!....148

Full Tests....148

Unit Tests....157

Review....159

Chapter 11. Authentication and Authorization....160

Preview....160

Interlude 1: Do You Need Authentication?....161

Authentication Methods....162

Global Authentication: Shared Secret....162

Simple Individual Authentication....165

Fancier Individual Authentication....166

OAuth2....167

User Model....168

User Data Layer....168

User Fake Data Layer....170

User Service Layer....171

User Web Layer....173

Test!....175

Top Layer....175

Authentication Steps....175

JWT....176

Third-Party Authentication: OIDC....176

Authorization....177

Middleware....178

CORS....179

Third-Party Packages....180

Review....180

Chapter 12. Testing....182

Preview....182

Web API Testing....182

Where to Test....183

What to Test....183

Pytest....184

Layout....185

Automated Unit Tests....185

Mocking....185

Test Doubles and Fakes....188

Web....190

Service....192

Data....194

Automated Integration Tests....195

The Repository Pattern....196

Automated Full Tests....197

Security Testing....199

Load Testing....199

Review....200

Chapter 13. Production....202

Preview....202

Deployment....202

Multiple Workers....203

HTTPS....204

Docker....204

Cloud Services....205

Kubernetes....205

Performance....205

Async....205

Caches....206

Databases, Files, and Memory....206

Queues....206

Python Itself....207

Troubleshooting....207

Kinds of Problems....207

Logging....208

Metrics....208

Review....208

Part IV. A Gallery....210

Chapter 14. Databases, Data Science, and a Little AI....212

Preview....212

Data Storage Alternatives....212

Relational Databases and SQL....213

SQLAlchemy....214

SQLModel....215

SQLite....216

PostgreSQL....216

EdgeDB....216

Nonrelational (NoSQL) Databases....217

Redis....217

MongoDB....217

Cassandra....217

Elasticsearch....218

NoSQL Features in SQL Databases....218

Database Load Testing....218

Data Science and AI....220

Review....222

Chapter 15. Files....224

Preview....224

Multipart Support....224

Uploading Files....224

File()....225

UploadFile....226

Downloading Files....227

FileResponse....227

StreamingResponse....228

Serving Static Files....228

Review....230

Chapter 16. Forms and Templates....232

Preview....232

Forms....232

Templates....234

Review....237

Chapter 17. Data Discovery and Visualization....238

Preview....238

Python and Data....238

PSV Text Output....239

csv....239

python-tabulate....240

pandas....241

SQLite Data Source and Web Output....242

Chart/Graph Packages....242

Chart Example 1: Test....243

Chart Example 2: Histogram....245

Map Packages....246

Map Example....247

Review....249

Chapter 18. Games....250

Preview....250

Python Game Packages....250

Splitting Game Logic....251

Game Design....251

Web Part One: Game Initialization....252

Web Part Two: Game Steps....253

Service Part One: Initialization....255

Service Part Two: Scoring....255

Test!....256

Data: Initialization....257

Let’s Play Cryptonamicon....257

Review....259

Appendix A. Further Reading....260

Python....260

FastAPI....261

Starlette....262

Pydantic....262

Appendix B. Creatures and Humans....264

Creatures....265

Explorers....267

Explorer Publications....267

Other Sources....268

Index....270

About the Author....278

Colophon....278

FastAPI is a young yet solid framework that takes advantage of newer Python features in a clean design. As its name implies, FastAPI is indeed fast, rivaling similar frameworks in languages such as Golang. With this practical book, developers familiar with Python will learn how FastAPI lets you accomplish more in less time with less code.

Author Bill Lubanovic covers the nuts and bolts of FastAPI development with how-to guides on various topics such as forms, database access, graphics, maps, and more that will take you beyond the basics. This book also includes how-to guides that will get you up to speed on RESTful APIs, data validation, authorization, and performance. With its similarities to frameworks like Flask and Django, you'll find it easy to get started with FastAPI.

• Through the course of this book, you will:
• Learn how to build web applications with FastAPI
• Understand the differences between FastAPI, Starlette, and pydantic
• Learn two features that set FastAPI apart: asynchronous functions and data type checking and validation
• Examine new features of Python 3.8+, especially type annotations
• Understand the differences between sync and async Python
• Learn how to connect with external APIs and services