from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### 📁

🔜 🎏 🏗 📁 ✍ 📁 `Dockerfile` ⏮️:

```{ .dockerfile .annotate }
# (1)
FROM python:3.9

# (2)
WORKDIR /code

{!../../docs_src/bigger_applications/app/routers/items.py!}
```

Como o caminho de cada *operação de rota* deve começar com `/`, como em:

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...o prefixo não deve incluir um `/` final.

Então, o prefixo neste caso é `/items`.

if (this.options.highlightName) {\n        name = name.replace(\n          regExp,\n          str => {\n            return `<strong class=\"${this.options.highlightClass}\">${str}</strong>`\n          }\n        )\n      }\n\n      if (this.options.highlightPath) {\n        path = path.replace(\n          regExp,\n          str => {\n            return `<strong class=\"${this.options.highlightClass}\">${str}</strong>`\n          }\n        )\n      }\n    }\n\n    const groupItemElement = $('<a/>',...

#### 🇸🇲 👗 & Pydantic 👗

👀 👈 🇸🇲 *🏷* 🔬 🔢 ⚙️ `=`, & 🚶‍♀️ 🆎 🔢 `Column`, 💖:

```Python
name = Column(String)
```

⏪ Pydantic *🏷* 📣 🆎 ⚙️ `:`, 🆕 🆎 ✍ ❕/🆎 🔑:

```Python
name: str
```

✔️ ⚫️ 🤯, 👆 🚫 🤚 😕 🕐❔ ⚙️ `=` & `:` ⏮️ 👫.

### ✍ Pydantic *🏷* / 🔗 👂 / 📨

🔜 ✍ Pydantic *🏷* (🔗) 👈 🔜 ⚙️ 🕐❔ 👂 💽, 🕐❔ 🛬 ⚫️ ⚪️➡️ 🛠️.

{!../../docs_src/bigger_applications/app/routers/items.py!}
```

由于每个*路径操作*的路径都必须以 `/` 开头，例如：

```Python hl_lines="1"
@router.get("/{item_id}")
async def read_item(item_id: str):
    ...
```

...前缀不能以 `/` 作为结尾。

因此，本例中的前缀为 `/items`。

我们还可以添加一个 `tags` 列表和额外的 `responses` 列表，这些参数将应用于此路由器中包含的所有*路径操作*。

我们可以添加一个 `dependencies` 列表，这些依赖项将被添加到路由器中的所有*路径操作*中，并将针对向它们发起的每个请求执行/解决。

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile

Now in the same project directory create a file `Dockerfile` with:

```{ .dockerfile .annotate }
# (1)!
FROM python:3.9

	#line 1 "not-int-const"
	void __cgo_f_1_3(void) { enum { __cgo_undefined__3 = (foo)*1 }; }
	#line 1 "not-num-const"
	void __cgo_f_1_4(void) { static const double __cgo_undefined__4 = (foo); }
	#line 1 "not-str-lit"
	void __cgo_f_1_5(void) { static const char __cgo_undefined__5[] = (foo); }

This program will not compile, but cgo can use the presence or absence
of an error message on a given line to deduce the information it

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile

В этой же директории создайте файл `Dockerfile` и заполните его:

```{ .dockerfile .annotate }
# (1)
FROM python:3.9

	FMOVD	8(R1), F2 // 220440fd
	FMOVQ	32(R5), F2 // a208c03d
	FMOVQ	65520(R10), F10 // 4afdff3d
	FMOVQ	64(RSP), F11    // eb13c03d

// medium offsets that either fit a single instruction or can use add+ldr/str
	MOVD -4095(R17), R3                        // 3bfe3fd1630340f9
	MOVD -391(R17), R3                         // 3b1e06d1630340f9
	MOVD -257(R17), R3                         // 3b0604d1630340f9

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

### Dockerfile

Agora, no mesmo diretório do projeto, crie um arquivo `Dockerfile` com:

```{ .dockerfile .annotate }
# (1)