* Numbers (`int`, `float`) with min and max values, etc.

* Validation for more exotic types, like:
    * URL.
    * Email.
    * UUID.
    * ...and others.

All the validation is handled by the well-established and robust **Pydantic**.

### Security and authentication { #security-and-authentication }

Security and authentication integrated. Without any compromise with databases or data models.

There are many situations in which you need to notify an error to a client that is using your API.

This client could be a browser with a frontend, a code from someone else, an IoT device, etc.

You could need to tell the client that:

* The client doesn't have enough privileges for that operation.
* The client doesn't have access to that resource.
* The item the client was trying to access doesn't exist.
* etc.

      HashCode that = (HashCode) object;
      return bits() == that.bits() && equalsSameBits(that);
    }
    return false;
  }

  /**
   * Returns a "Java hash code" for this {@code HashCode} instance; this is well-defined (so, for
   * example, you can safely put {@code HashCode} instances into a {@code HashSet}) but is otherwise
   * probably not what you want to use.
   */
  @Override
  public final int hashCode() {

See https://github.com/twbs/bootstrap/issues/26878\n  overflow: hidden;\n  vertical-align: middle;\n}\n\n\n//\n// Tables\n//\n\ntable {\n  border-collapse: collapse; // Prevent double borders\n}\n\ncaption {\n  padding-top: $table-cell-padding;\n  padding-bottom: $table-cell-padding;\n  color: $table-caption-color;\n  text-align: left;\n  caption-side: bottom;\n}\n\n// 1. Removes font-weight bold by inheriting\n// 2. Matches default `<td>` alignment by inheriting `text-align`.\n// 3. Fix alignment for...

                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    // Put the sets in different orders for the hell of it
                    return union(
                        new LinkedHashSet<>(asList(elements[0], elements[1], elements[2])),
                        new LinkedHashSet<>(asList(elements[1], elements[0], elements[2])));

At the same point, you try to trigger the autocomplete with `Ctrl+Space` and you see:

<img src="/img/python-types/image02.png">

With that, you can scroll, seeing the options, until you find the one that "rings a bell":

<img src="/img/python-types/image03.png">

## More motivation { #more-motivation }

Check this function, it already has type hints:

{* ../../docs_src/python_types/tutorial003_py39.py hl[1] *}

 * synonym rules. The file format supports both explicit mappings (e.g., `a => b`)
 * and equivalent synonyms (e.g., `a, b, c`).
 *
 * The class provides methods for retrieving, adding, updating, and
 * deleting synonym items, as well as reloading the dictionary
 * from its source file.
 */
public class SynonymFile extends DictionaryFile<SynonymItem> {
    private static final String SYNONYM = "synonym";

 * asymptotics but requires O(n) memory, and a {@code PriorityQueue} implementation takes O(n log
 * k). In benchmarks, this implementation performs at least as well as either implementation, and
 * degrades more gracefully for worst-case input.
 *
 * <p>The implementation does not necessarily use a <i>stable</i> sorting algorithm; when multiple

---

**FastAPI** doesn't make any compromise with any database, data model or tool.

It gives you all the flexibility to choose the ones that fit your project the best.

And you can use directly many well maintained and widely used packages like `pwdlib` and `PyJWT`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

 *
 * <ul>
 *   <li><b>collision-resistant:</b> while the definition above requires making at least <i>some</i>
 *       token attempt, one measure of the quality of a hash function is <i>how well</i> it succeeds
 *       at this goal. Important note: it may be easy to achieve the theoretical minimum collision
 *       rate when using completely <i>random</i> sample input. The true test of a hash function is