/*
 * Copyright (C) 2009 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

### Utiliser le paramètre `response_model_exclude_unset` { #use-the-response-model-exclude-unset-parameter }

Vous pouvez définir le paramètre du *décorateur de chemin d'accès* `response_model_exclude_unset=True` :

{* ../../docs_src/response_model/tutorial004_py310.py hl[22] *}

FastAPI 自 0.95.0 版起加入並開始推薦使用 `Annotated`。

如果你的版本較舊，嘗試使用 `Annotated` 會出錯。

請先至少 [升級 FastAPI 版本](../deployment/versions.md#upgrading-the-fastapi-versions) 到 0.95.1 再使用 `Annotated`。

///

## 在 `q` 參數的型別中使用 `Annotated` { #use-annotated-in-the-type-for-the-q-parameter }

還記得先前在 [Python 型別介紹](../python-types.md#type-hints-with-metadata-annotations) 提到可以用 `Annotated` 為參數加入中繼資料嗎？

現在就用在 FastAPI 上吧。🚀

我們原本的型別註記是：

```Python

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2012 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2008 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

        src[0] = 0x20;

        // Encode "AB" followed by non-space padding
        src[1] = 'E';
        src[2] = 'B'; // A
        src[3] = 'E';
        src[4] = 'C'; // B

        // Use 'X' (0x58) instead of space for padding
        for (int i = 5; i < 31; i += 2) {
            src[i] = 'E';
            src[i + 1] = 'I'; // Encodes to 'X'
        }

        src[31] = 'C';
        src[32] = 'A';