from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None
    tags: set[str] = set()


@app.post("/items/", response_model=Item, tags=["items"])
async def create_item(item: Item):
    return item


@app.get("/items/", tags=["items"])
async def read_items():

"RollingUpdate" }} rollingUpdate: maxSurge: {{ .Values.DeploymentUpdate.maxSurge }} maxUnavailable: {{ .Values.DeploymentUpdate.maxUnavailable }} {{- end}} replicas: 1 selector: matchLabels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} template: metadata: name: {{ template "minio.fullname" . }} labels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} {{- if .Values.podLabels }} {{ toYaml .Values.podLabels | indent 8 }} {{- end }} annotations: checksum/secrets: {{ include...

"RollingUpdate" }} rollingUpdate: maxSurge: {{ .Values.DeploymentUpdate.maxSurge }} maxUnavailable: {{ .Values.DeploymentUpdate.maxUnavailable }} {{- end}} replicas: 1 selector: matchLabels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} template: metadata: name: {{ template "minio.fullname" . }} labels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} {{- if .Values.podLabels }} {{ toYaml .Values.podLabels | indent 8 }} {{- end }} annotations: checksum/secrets: {{ include...

"RollingUpdate" }} rollingUpdate: maxSurge: {{ .Values.DeploymentUpdate.maxSurge }} maxUnavailable: {{ .Values.DeploymentUpdate.maxUnavailable }} {{- end}} replicas: 1 selector: matchLabels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} template: metadata: name: {{ template "minio.fullname" . }} labels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} {{- if .Values.podLabels }} {{ toYaml .Values.podLabels | indent 8 }} {{- end }} annotations: checksum/secrets: {{ include...

"RollingUpdate" }} rollingUpdate: maxSurge: {{ .Values.DeploymentUpdate.maxSurge }} maxUnavailable: {{ .Values.DeploymentUpdate.maxUnavailable }} {{- end}} replicas: 1 selector: matchLabels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} template: metadata: name: {{ template "minio.fullname" . }} labels: app: {{ template "minio.name" . }} release: {{ .Release.Name }} {{- if .Values.podLabels }} {{ toYaml .Values.podLabels | indent 8 }} {{- end }} annotations: checksum/secrets: {{ include...

</div>

## 示例

### 创建

* 创建一个 `main.py` 文件并写入以下内容:

```Python
from typing import Union

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}
```

<details markdown="1">

```

</div>

而当其它文件导入它时并不会被调用，像这样：

```Python
from myapp import app
```

#### 更多细节

假设你的文件命名为 `myapp.py`。

如果你这样运行：

<div class="termy">

```console
$ python myapp.py
```

</div>

那么文件中由 Python 自动创建的内部变量 `__name__`，会将字符串 `"__main__"` 作为值。

所以，下面这部分代码才会运行：

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

---

如果你是导入这个模块（文件）就不会这样。

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float = 10.5
    tags: list[str] = []


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The bartenders", "price": 62, "tax": 20.2},

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Item = Body(
        examples=[
            {
                "name": "Foo",
                "description": "A very nice Item",

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: str | None = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")
async def read_items(commons: CommonQueryParams = Depends(CommonQueryParams)):
    response = {}