import java.util.stream.IntStream;
import javax.annotation.CheckForNull;

/**
 * An immutable array of {@code int} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code int[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link

You can combine normal FastAPI *path operations* with GraphQL on the same application.

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

Make sure you evaluate if the **benefits** for your use case compensate the **drawbacks**. 🤓

///

## GraphQL Libraries

import java.util.stream.LongStream;
import javax.annotation.CheckForNull;

/**
 * An immutable array of {@code long} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code long[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link

import java.util.stream.IntStream;
import javax.annotation.CheckForNull;

/**
 * An immutable array of {@code int} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code int[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link

import java.util.stream.DoubleStream;
import javax.annotation.CheckForNull;

/**
 * An immutable array of {@code double} values, with an API resembling {@link List}.
 *
 * <p>Advantages compared to {@code double[]}:
 *
 * <ul>
 *   <li>All the many well-known advantages of immutability (read <i>Effective Java</i>, third
 *       edition, Item 17).
 *   <li>Has the value-based (not identity-based) {@link #equals}, {@link #hashCode}, and {@link

## Requirements

After testing several alternatives, I decided that I was going to use <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">**Pydantic**</a> for its advantages.

Then I contributed to it, to make it fully compliant with JSON Schema, to support different ways to define constraint declarations, and to improve editor support (type checks, autocompletion) based on the tests in several editors.

/// tip

For new code and whenever possible, use `Annotated` as explained above. There are multiple advantages (explained below) and no disadvantages. 🍰

///

This is how you would use `Query()` as the default value of your function parameter, setting the parameter `max_length` to 50:

//// tab | Python 3.10+

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python hl_lines="12"
{!> ../../docs_src/request_files/tutorial001.py!}
```

////

Using `UploadFile` has several advantages over `bytes`:

* You don't have to use `File()` in the default value of the parameter.
* It uses a "spooled" file:

This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

Using Linux containers has several advantages including **security**, **replicability**, **simplicity**, and others.

/// tip

In a hurry and already know this stuff? Jump to the [`Dockerfile` below 👇](#build-a-docker-image-for-fastapi).

///

<details>