Marshmallow and Webargs provide validation, parsing and serialization as plug-ins.

But documentation is still missing. Then APISpec was created.

It is a plug-in for many frameworks (and there's a plug-in for Starlette too).

The way it works is that you write the definition of the schema using YAML format inside the docstring of each function handling a route.

And it generates OpenAPI schemas.

# Concurrency and async / await { #concurrency-and-async-await }

Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry? { #in-a-hurry }

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by

                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by

A foundational Java library providing essential utilities and components for the CodeLibs project ecosystem. Built with Java 21 and optimized for modern Java development patterns including pattern matching, switch expressions, and sequenced collections.

## ✨ Features

### Core Utilities
- **Bean Manipulation** (`org.codelibs.core.beans`) - JavaBeans metadata handling, property access, and object conversion with comprehensive `BeanDesc` system

{* ../../docs_src/security/tutorial005_an_py310.py hl[106,108:116] *}

## Verify the `username` and data shape { #verify-the-username-and-data-shape }

We verify that we get a `username`, and extract the scopes.

And then we validate that data with the Pydantic model (catching the `ValidationError` exception), and if we get an error reading the JWT token or validating the data with Pydantic, we raise the `HTTPException` we created before.

Replication relies on immutability provided by versioning to sync objects between the configured source and replication target. Replication results in the object data, metadata, last modification time and version ID all being identical between the source and target. Thus version ordering is automatically guaranteed on the source and target clusters.

### Replication of object version and metadata

    val tagAndClass = source.readByte().toInt() and 0xff
    val tagClass = tagAndClass and 0b1100_0000
    val constructed = (tagAndClass and 0b0010_0000) == 0b0010_0000
    val tag =
      when (val tag0 = tagAndClass and 0b0001_1111) {
        0b0001_1111 -> readVariableLengthLong()
        else -> tag0.toLong()
      }

    // Read the length.
    val length0 = source.readByte().toInt() and 0xff
    val length =
      when {

* How to set **validation constraints** as `maximum_length` or `regex`.
* A very powerful and easy to use **<dfn title="also known as components, resources, providers, services, injectables">Dependency Injection</dfn>** system.
* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth.

// implementation-specific way and writes the result to standard error.
// Print is useful for bootstrapping and debugging; it is not guaranteed
// to stay in the language.
func print(args ...Type)

// The println built-in function formats its arguments in an
// implementation-specific way and writes the result to standard error.
// Spaces are always added between arguments and a newline is appended.