## Instalar `PyJWT` { #install-pyjwt }

Nós precisamos instalar o `PyJWT` para criar e verificar os tokens JWT em Python.

Certifique-se de criar um [ambiente virtual](../../virtual-environments.md){.internal-link target=_blank}, ativá-lo e então instalar o `pyjwt`:

<div class="termy">

```console

```

////


/// info

想进一步了解 <a href="https://docs.pydantic.dev/" class="external-link" target="_blank">Pydantic，请阅读其文档</a>.

///

整个 **FastAPI** 建立在 Pydantic 的基础之上。

实际上你将在 [教程 - 用户指南](tutorial/index.md){.internal-link target=_blank} 看到很多这种情况。

## **FastAPI** 中的类型提示

**FastAPI** 利用这些类型提示来做下面几件事。

使用 **FastAPI** 时用类型提示声明参数可以获得：

* **编辑器支持**。

/**
 * Adapter to convert an {@link Enumeration} to an {@link Iterator}.
 *
 * @author shot
 * @param <T> the element type
 */
public class EnumerationIterator<T> implements Iterator<T> {

    private Enumeration<T> enumeration = null;

    /**
     * Returns an {@link Iterable} that wraps an {@link Enumeration} for use in a for-each statement.
     *

* <a href="https://hub.docker.com/_/postgres" class="external-link" target="_blank">PostgreSQL</a>
* <a href="https://hub.docker.com/_/mysql" class="external-link" target="_blank">MySQL</a>
* <a href="https://hub.docker.com/_/mongo" class="external-link" target="_blank">MongoDB</a>
* <a href="https://hub.docker.com/_/redis" class="external-link" target="_blank">Redis</a>, etc.

import org.xml.sax.helpers.DefaultHandler;

/**
 * Utility class for {@link SAXParser}.
 *
 * @author higa
 */
public abstract class SAXParserUtil {

    /**
     * Do not instantiate.
     */
    protected SAXParserUtil() {
    }

    /**
     * Parses the content of the specified {@link InputSource} as XML using the specified {@link DefaultHandler}.
     *
     * @param parser

     * that is given by {@link #getSource()}.
     *
     * @return The one-based index of the column containing the problem or non-positive value if unknown.
     */
    int getColumnNumber();

    /**
     * Gets the location of the problem. The location is a user-friendly combination of the values from
     * {@link #getSource()}, {@link #getLineNumber()} and {@link #getColumnNumber()}. The exact syntax of the returned

        }
    }

    /**
     * Returns the value of a {@literal static} {@link Field} as a {@link String}.
     *
     * @param field the field (must not be {@literal null})
     * @return the field value
     * @throws IllegalAccessRuntimeException {@link IllegalAccessException} if an error occurs
     * @see #getString(Field, Object)
     */

 * methods use {@link URL} parameters, they are usually not appropriate for HTTP or other
 * non-classpath resources.
 *
 * @author Chris Nokleberg
 * @author Ben Yu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class Resources {
  private Resources() {}

  /**
   * Returns a {@link ByteSource} that reads from the given URL.
   *

              <location>${project.basedir}/javadoc-link/error_prone_annotations</location>
            </offlineLink>
          </offlineLinks>
          <links>
            <link>https://docs.oracle.com/en/java/javase/25/docs/api/</link>
            <link>https://jspecify.dev/docs/api/</link>
          </links>
          <overview>../../overview.html</overview>
        </configuration>
      </plugin>

    }

    /**
     * Creates a new instance of {@link SAXParser} using the default configuration of {@link SAXParserFactory}.
     *
     * @return A new instance of {@link SAXParser}.
     */
    public static SAXParser newSAXParser() {
        return newSAXParser(newInstance());
    }

    /**
     * Creates a new instance of {@link SAXParser} using the specified {@link SAXParserFactory}.
     *
     * @param factory