* It contains an `app/main.py` file. As it is inside a Python package (a directory with a file `__init__.py`), it is a "module" of that package: `app.main`.
* There's also an `app/dependencies.py` file, just like `app/main.py`, it is a "module": `app.dependencies`.

 ╭─ <font color="#8AE234"><b>Python module file</b></font> ─╮
 │                      │
 │  🐍 main.py          │
 │                      │
 ╰──────────────────────╯

<font color="#3465A4">INFO    </font> Importing module <font color="#4E9A06">main</font>
<font color="#3465A4">INFO    </font> Found importable FastAPI app

]

[tool.mypy]
strict = true

[[tool.mypy.overrides]]
module = "fastapi.concurrency"
warn_unused_ignores = false
ignore_missing_imports = true

[[tool.mypy.overrides]]
module = "fastapi.tests.*"
ignore_missing_imports = true
check_untyped_defs = true

[[tool.mypy.overrides]]
module = "docs_src.*"
disallow_incomplete_defs = false
disallow_untyped_defs = false

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient


@pytest.fixture(name="app", scope="module")
def get_app():
    with pytest.warns(DeprecationWarning):
        from docs_src.events.tutorial002 import app
    yield app


def test_events(app: FastAPI):
    with TestClient(app) as client:
        response = client.get("/items/")
        assert response.status_code == 200, response.text

These types that have internal types are called "**generic**" types. And it's possible to declare them, even with their internal types.

To declare those types and the internal types, you can use the standard Python module `typing`. It exists specifically to support these type hints.

#### Newer versions of Python

 ╭─ <font color="#8AE234"><b>Python module file</b></font> ─╮
 │                      │
 │  🐍 main.py          │
 │                      │
 ╰──────────────────────╯

<font color="#3465A4">INFO    </font> Importing module <font color="#4E9A06">main</font>
<font color="#3465A4">INFO    </font> Found importable FastAPI app

!!! info
    Note that the `TestClient` receives data that can be converted to JSON, not Pydantic models.

    If you have a Pydantic model in your test and you want to send its data to the application during testing, you can use the `jsonable_encoder` described in [JSON Compatible Encoder](encoder.md){.internal-link target=_blank}.

## Run it

### Virtual environment with `venv`

You can create an isolated virtual local environment in a directory using Python's `venv` module. Let's do this in the cloned repository (where the `requirements.txt` is):

<div class="termy">

```console
$ python -m venv env
```

</div>

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note "備考"
    `uvicorn main:app`は以下を示します:

    * `main`: `main.py`ファイル (Python "module")。
    * `app`:  `main.py`内部で作られるobject（`app = FastAPI()`のように記述される）。
    * `--reload`: コードの変更時にサーバーを再起動させる。開発用。

出力には次のような行があります:

```hl_lines="4"

import os
from pathlib import Path

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(scope="module")
def client():
    static_dir: Path = Path(os.getcwd()) / "static"
    print(static_dir)
    static_dir.mkdir(exist_ok=True)
    from docs_src.custom_docs_ui.tutorial002 import app

    with TestClient(app) as client:
        yield client
    static_dir.rmdir()