Let's say you have a Pydantic model with default values, like this one:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:7] hl[7] *}

### Model for Input { #model-for-input }

If you use this model as an input like here:

{* ../../docs_src/separate_openapi_schemas/tutorial001_py310.py ln[1:15] hl[14] *}

...then the `description` field will **not be required**. Because it has a default value of `None`.

{* ../../docs_src/sub_applications/tutorial001.py hl[3,6:8] *}

### Sub-aplicação

Em seguida, crie sua sub-aplicação e suas *operações de rota*.

Essa sub-aplicação é apenas outra aplicação FastAPI padrão, mas esta é a que será "montada":

{* ../../docs_src/sub_applications/tutorial001.py hl[11,14:16] *}

### Monte a sub-aplicação

🤶 Ⓜ. `pip install python-multipart`.

///

## 🗄 `File` & `Form`

{* ../../docs_src/request_forms_and_files/tutorial001.py hl[1] *}

## 🔬 `File` & `Form` 🔢

✍ 📁 & 📨 🔢 🎏 🌌 👆 🔜 `Body` ⚖️ `Query`:

{* ../../docs_src/request_forms_and_files/tutorial001.py hl[8] *}

📁 & 📨 🏑 🔜 📂 📨 📊 & 👆 🔜 📨 📁 & 📨 🏑.

& 👆 💪 📣 📁 `bytes` & `UploadFile`.

/// warning

///

## Mehrere Modelle

Hier der generelle Weg, wie die Modelle mit ihren Passwort-Feldern aussehen könnten, und an welchen Orten sie verwendet werden würden.

{* ../../docs_src/extra_models/tutorial001_py310.py hl[7,9,14,20,22,27:28,31:33,38:39] *}

/// info

In Pydantic v1 hieß diese Methode `.dict()`, in Pydantic v2 wurde sie deprecated (aber immer noch unterstützt) und in `.model_dump()` umbenannt.

{* ../../docs_src/security/tutorial005_an_py310.py hl[5,9,13,47,65,106,108:116,122:125,129:135,140,156] *}

Ahora revisemos esos cambios paso a paso.

## Esquema de seguridad OAuth2

Nesse caso, o caminho original `/app` seria servido em `/api/v1/app`.

Embora todo o seu código esteja escrito assumindo que existe apenas `/app`.

{* ../../docs_src/behind_a_proxy/tutorial001.py hl[6] *}

Veamos de nuevo el ejemplo anterior:

{* ../../docs_src/response_status_code/tutorial001.py hl[6] *}

`201` es el código de estado para "Created".

Pero no tienes que memorizar lo que significa cada uno de estos códigos.

Puedes usar las variables de conveniencia de `fastapi.status`.

{* ../../docs_src/response_status_code/tutorial002.py hl[1,6] *}

///

## Multiple models { #multiple-models }

Here's a general idea of how the models could look like with their password fields and the places where they are used:

{* ../../docs_src/extra_models/tutorial001_py310.py hl[7,9,14,20,22,27:28,31:33,38:39] *}


/// info

In Pydantic v1 the method was called `.dict()`, it was deprecated (but still supported) in Pydantic v2, and renamed to `.model_dump()`.

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

🥇 🍕 🔢, ⏭ `yield`, 🔜 🛠️ **⏭** 🈸 ▶️.

& 🍕 ⏮️ `yield` 🔜 🛠️ **⏮️** 🈸 ✔️ 🏁.

### 🔁 🔑 👨‍💼

🚥 👆 ✅, 🔢 🎀 ⏮️ `@asynccontextmanager`.

👈 🗜 🔢 🔘 🕳 🤙 "**🔁 🔑 👨‍💼**".

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

**🔑 👨‍💼** 🐍 🕳 👈 👆 💪 ⚙️ `with` 📄, 🖼, `open()` 💪 ⚙️ 🔑 👨‍💼:

{* ../../docs_src/first_steps/tutorial001.py hl[7] *}

Đây là một hàm Python.

Nó sẽ được gọi bởi **FastAPI** bất cứ khi nào nó nhận một request tới URL "`/`" sử dụng một toán tử `GET`.

Trong trường hợp này, nó là một hàm `async`.

---

Bạn cũng có thể định nghĩa nó như là một hàm thông thường thay cho `async def`:

{* ../../docs_src/first_steps/tutorial003.py hl[7] *}

/// note