For example, it was clear that ideally it should be based on standard Python type hints.

Also, the best approach was to use already existing standards.

So, before even starting to code **FastAPI**, I spent several months studying the specs for OpenAPI, JSON Schema, OAuth2, etc. Understanding their relationship, overlap, and differences.

API changes
-----------

We make changes to Guava's public [APIs][], including adding new APIs, very
carefully. Because of this, if you're interested in seeing a new feature in
Guava, the best approach is to create an [issue][] (or comment on an existing
issue if there is one) requesting the feature and describing specific use cases
for it.

If we decide to pursue a feature request, it will go through a thorough process

But this example is still valid and it shows how to interact with the internal components.

///

We can also use this same approach to access the request body in an exception handler.

All we need to do is handle the request inside a `try`/`except` block:

{* ../../docs_src/custom_request_and_route/tutorial002_an_py310.py hl[14,16] *}

    }
  }

  private static @Nullable Field getInheritableThreadLocalsField() {
    if (isAndroid()) {
      /*
       * We need not worry about class unloading under Android. Plus, this approach doesn't always
       * work under Android.
       *
       * (Clearing inheritableThreadLocals could still be useful independent of class unloading, but

    @Override
    public @Nullable Class<?> loadFinalizer() {
      if (disabled) {
        return null;
      }
      if (isAndroid()) {
        // We need not worry about class unloading under Android. Plus, this approach wouldn't work.
        return null;
      }
      ClassLoader systemLoader;
      try {
        systemLoader = ClassLoader.getSystemClassLoader();
      } catch (SecurityException e) {

    @Override
    public @Nullable Class<?> loadFinalizer() {
      if (disabled) {
        return null;
      }
      if (isAndroid()) {
        // We need not worry about class unloading under Android. Plus, this approach wouldn't work.
        return null;
      }
      ClassLoader systemLoader;
      try {
        systemLoader = ClassLoader.getSystemClassLoader();
      } catch (SecurityException e) {

# FastAPI in Containers - Docker { #fastapi-in-containers-docker }

When deploying FastAPI applications a common approach is to build a **Linux container image**. It's normally done using [**Docker**](https://www.docker.com/). You can then deploy that container image in one of a few possible ways.

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

/// tip

    }
  }

  private static @Nullable Field getInheritableThreadLocalsField() {
    if (isAndroid()) {
      /*
       * We need not worry about class unloading under Android. Plus, this approach doesn't always
       * work under Android.
       *
       * (Clearing inheritableThreadLocals could still be useful independent of class unloading, but

  /**
   * Common interface for retrieving a 64-bit long from a little-endian byte array.
   *
   * <p>This abstraction allows us to use single-instruction load and put when available, or fall
   * back on the slower approach of using Longs.fromBytes(byte...).
   */
  @VisibleForTesting
  interface LittleEndianBytes {
    long getLongLittleEndian(byte[] array, int offset);

 *       <strong>AND</strong> this stream was constructed with {@linkplain
 *       #FileBackedOutputStream(int, boolean) the two-arg constructor} with {@code true} for the
 *       second parameter. Relying on this second approach is discouraged.
 * </ul>
 *
 * <p>This class is thread-safe.
 *
 * @author Chris Nokleberg
 * @since 1.0
 */
@Beta
@J2ktIncompatible
@GwtIncompatible
@J2ObjCIncompatible