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


items = {
    "foo": {"name": "Foo", "price": 50.2},
    "bar": {"name": "Bar", "description": "The Bar fighters", "price": 62, "tax": 20.2},
    "baz": {
        "name": "Baz",
        "description": "There goes my baz",

from typing import Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: float = 10.5


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

# Form Data { #form-data }

When you need to receive form fields instead of JSON, you can use `Form`.

/// 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
```

        rsession.setLocalRepositoryManager(system.newLocalRepositoryManager(rsession, localRepo));

        rsession.setTransferListener(Mockito.mock(TransferListener.class));
        rsession.setRepositoryListener(Mockito.mock(RepositoryListener.class));

        DefaultMavenExecutionRequest request = new DefaultMavenExecutionRequest();

true jar Does nothing. runtime false true false false false true org.apache.maven.plugin.coreit.ItMojo java per-lookup once-per-session org.apache.maven maven-plugin-api jar 2.0 org/apache/maven/plugin/coreit/ItMojo.class package org.apache.maven.plugin.coreit; public synchronized class ItMojo extends org.apache.maven.plugin.AbstractMojo { public void ItMojo(); public void execute(); } pom.xml 4.0.0 org.apache.maven.plugins maven-jar-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin...

### 关于 `__name__ == "__main__"`

`__name__ == "__main__"` 的主要目的是使用以下代码调用文件时执行一些代码：

<div class="termy">

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

</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>

            RepositorySystem repositorySystem;
            try {
                repositorySystem = container.lookup(RepositorySystem.class);
            } catch (ComponentLookupException e) {
                throw new IllegalStateException("Unable to lookup " + RepositorySystem.class.getName());
            }

            if (mirrors) {
                repositorySystem.injectMirror(session, repositories);
            }

Para fazer isso, use a anotação de tipo padrão do Python <a href="https://docs.python.org/3/library/typing.html#typing.Union" class="external-link" target="_blank">`typing.Union`</a>:

/// note | Nota

from fastapi import FastAPI, Form
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class ItemGroup(BaseModel):
    items: list[tuple[str, str]]


class Coordinate(BaseModel):
    x: float
    y: float


@app.post("/model-with-tuple/")
def post_model_with_tuple(item_group: ItemGroup):
    return item_group


@app.post("/tuple-of-models/")

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

@ExtendWith(MockKExtension::class)
class ApplyDefaultConfigurationTest {
    init {
        DslContext.initForTest()
    }

    @MockK(relaxed = true)
    lateinit var buildType: BaseGradleBuildType

    private val steps = BuildSteps()