///

### Step 2: create a `FastAPI` "instance" { #step-2-create-a-fastapi-instance }

{* ../../docs_src/first_steps/tutorial001_py39.py hl[3] *}

Here the `app` variable will be an "instance" of the class `FastAPI`.

This will be the main point of interaction to create all your API.

import org.codehaus.plexus.interpolation.QueryEnabledValueSource;

/**
 * Wraps an arbitrary object with an {@link ObjectBasedValueSource} instance, then
 * wraps that source with a {@link PrefixedValueSourceWrapper} instance, to which
 * this class delegates all of its calls.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")

	set -x
fi

pkill minio
pkill kes
rm -rf /tmp/xl

go install -v github.com/minio/mc@master
cp -a $(go env GOPATH)/bin/mc ./mc

if [ ! -f ./kes ]; then
	wget --quiet -O kes https://github.com/minio/kes/releases/latest/download/kes-linux-amd64 &&
		chmod +x kes
fi

if ! openssl version &>/dev/null; then
	apt install openssl || sudo apt install opensssl
fi

# Start KES Server

// Code generated by "stringer -type=authType -trimprefix=authType auth-handler.go"; DO NOT EDIT.

package cmd

import "strconv"

func _() {
	// An "invalid array index" compiler error signifies that the constant values have changed.
	// Re-run the stringer command to generate them again.
	var x [1]struct{}
	_ = x[authTypeUnknown-0]
	_ = x[authTypeAnonymous-1]
	_ = x[authTypePresigned-2]
	_ = x[authTypePresignedV2-3]

  }

  /**
   * Creates an instance of {@link ToStringHelper} in the same manner as {@link
   * #toStringHelper(Object)}, but using the simple name of {@code clazz} instead of using an
   * instance's {@link Object#getClass()}.
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param clazz the {@link Class} of the instance
   * @since 18.0 (since 7.0 as {@code Objects.toStringHelper()}).

      }
      return new InternerImpl<>(mapMaker);
    }
  }

  /** Returns a fresh {@link InternerBuilder} instance. */
  public static InternerBuilder newBuilder() {
    return new InternerBuilder();
  }

  /**
   * Returns a new thread-safe interner which retains a strong reference to each instance it has
   * interned, thus preventing these instances from being garbage-collected. If this retention is

/// info

To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

## Import `Form` { #import-form }

  protected ForwardingObject() {}

  /**
   * Returns the backing delegate instance that methods are forwarded to. Abstract subclasses
   * generally override this method with an abstract method that has a more specific return type,
   * such as {@link ForwardingSet#delegate}. Concrete subclasses override this method to supply the
   * instance being decorated.
   */
  protected abstract Object delegate();

# 模板

**FastAPI** 支持多种模板引擎。

Flask 等工具使用的 Jinja2 是最用的模板引擎。

在 Starlette 的支持下，**FastAPI** 应用可以直接使用工具轻易地配置 Jinja2。

## 安装依赖项

安装 `jinja2`：

<div class="termy">

```console
$ pip install jinja2

---> 100%
```

</div>

## 使用 `Jinja2Templates`

* 导入 `Jinja2Templates`
* 创建可复用的 `templates` 对象
* 在返回模板的*路径操作*中声明 `Request` 参数

   * instance.
   */
  private final Map<Type, Integer> emptyInstanceGenerated = new HashMap<>();

  final <T> void addSampleInstances(Class<T> type, Iterable<? extends T> instances) {
    sampleInstances.putAll(checkNotNull(type), checkNotNull(instances));
  }

  /**
   * Returns a fresh instance for {@code type} if possible. The returned instance could be:
   *
   * <ul>