James Kaplan <******@****.***> 1558716101 -0700

class RequestValidationError(ValidationException):
    def __init__(self, errors: Sequence[Any], *, body: Any = None) -> None:
        super().__init__(errors)
        self.body = body


class WebSocketRequestValidationError(ValidationException):
    pass


class ResponseValidationError(ValidationException):
    def __init__(self, errors: Sequence[Any], *, body: Any = None) -> None:

Let's say you have a file structure like this:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   ├── dependencies.py
│   └── routers
│   │   ├── __init__.py
│   │   ├── items.py
│   │   └── users.py
│   └── internal
│       ├── __init__.py
│       └── admin.py
```

/// tip

There are several `__init__.py` files: one in each directory or subdirectory.

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

No arquivo `main.py` você tem seu aplicativo **FastAPI**:


```Python
{!../../docs_src/app_testing/main.py!}
```

### Arquivo de teste

Então você poderia ter um arquivo `test_main.py` com seus testes. Ele poderia estar no mesmo pacote Python (o mesmo diretório com um arquivo `__init__.py`):

``` hl_lines="5"
.
├── app

    group and organize permissions, you could do it as well in your application, just
    know that that it is application specific, it's not part of the specification.
    """

    def __init__(
        self,
        *,
        grant_type: Annotated[
            Union[str, None],
            Form(pattern="password"),
            Doc(
                """

{!../../docs_src/dependencies/tutorial011.py!}
```

本例中，**FastAPI**  使用 `__call__` 检查附加参数及子依赖项，稍后，还要调用它向*路径操作函数*传递值。

## 参数化实例

接下来，使用 `__init__` 声明用于**参数化**依赖项的实例参数：

```Python hl_lines="7"
{!../../docs_src/dependencies/tutorial011.py!}
```

本例中，**FastAPI** 不使用 `__init__`，我们要直接在代码中使用。

## 创建实例

使用以下代码创建类实例：

```Python hl_lines="16"
{!../../docs_src/dependencies/tutorial011.py!}
```

class Person:
    def __init__(self, name: str):
        self.name = name


def get_person_name(one_person: Person):

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

在 `main.py` 文件中你有一个 **FastAPI** app:


```Python
{!../../docs_src/app_testing/main.py!}
```

### 测试文件

然后你会有一个包含测试的文件 `test_main.py` 。app可以像Python包那样存在（一样是目录，但有个 `__init__.py` 文件）：

``` hl_lines="5"
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

from fastapi import Depends, FastAPI

app = FastAPI()


class FixedContentQueryChecker:
    def __init__(self, fixed_content: str):
        self.fixed_content = fixed_content

    def __call__(self, q: str = ""):
        if q:
            return self.fixed_content in q
        return False


checker = FixedContentQueryChecker("bar")


@app.get("/query-checker/")

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse


class UnicornException(Exception):
    def __init__(self, name: str):
        self.name = name


app = FastAPI()


@app.exception_handler(UnicornException)
async def unicorn_exception_handler(request: Request, exc: UnicornException):
    return JSONResponse(
        status_code=418,