# Extra Data Types

Up to now, you have been using common data types, like:

- `int`
- `float`
- `str`
- `bool`

But you can also use more complex data types.

And you will still have the same features as seen up to now:

- Great editor support.
- Data conversion from incoming requests.
- Data conversion for response data.
- Data validation.
- Automatic annotation and documentation.

## Other data types

Here are some of the additional data types you can use:

- `UUID`:
  - A standard "Universally Unique Identifier", common as an ID in many databases and systems.
  - In requests and responses will be represented as a `str`.
- `datetime.datetime`:
  - A Python `datetime.datetime`.
  - In requests and responses will be represented as a `str` in ISO 8601 format, like: `2008-09-15T15:53:00+05:00`.
- `datetime.date`:
  - Python `datetime.date`.
  - In requests and responses will be represented as a `str` in ISO 8601 format, like: `2008-09-15`.
- `datetime.time`:
  - A Python `datetime.time`.
  - In requests and responses will be represented as a `str` in ISO 8601 format, like: `14:23:55.003`.
- `datetime.timedelta`:
  - A Python `datetime.timedelta`.
  - In requests and responses will be represented as a `float` of total seconds.
  - Pydantic also allows representing it as an "ISO 8601 time diff encoding", [see the docs for more info](https://pydantic.dev/docs/validation/latest/concepts/serialization/#custom-serializers).
- `frozenset`:
  - In requests and responses, treated the same as a `set`:
    - In requests, a list will be read, eliminating duplicates and converting it to a `set`.
    - In responses, the `set` will be converted to a `list`.
    - The generated schema will specify that the `set` values are unique (using JSON Schema's `uniqueItems`).
- `bytes`:
  - Standard Python `bytes`.
  - In requests and responses will be treated as `str`.
  - The generated schema will specify that it's a `str` with `binary` "format".
- `Decimal`:
  - Standard Python `Decimal`.
  - In requests and responses, handled the same as a `float`.
- You can check all the valid Pydantic data types here: [Pydantic data types](https://pydantic.dev/docs/validation/latest/concepts/types/).

## Example

Here's an example _path operation_ with parameters using some of the above types.

```python
from datetime import datetime, time, timedelta
from typing import Annotated
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: Annotated[datetime, Body()],
    end_datetime: Annotated[datetime, Body()],
    process_after: Annotated[timedelta, Body()],
    repeat_at: Annotated[time | None, Body()] = None,
):
    start_process = start_datetime + process_after
    duration = end_datetime - start_process
    return {
        "item_id": item_id,
        "start_datetime": start_datetime,
        "end_datetime": end_datetime,
        "process_after": process_after,
        "repeat_at": repeat_at,
        "start_process": start_process,
        "duration": duration,
    }
```

Note that the parameters inside the function have their natural data type, and you can, for example, perform normal date manipulations, like:

```python
from datetime import datetime, time, timedelta
from typing import Annotated
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: Annotated[datetime, Body()],
    end_datetime: Annotated[datetime, Body()],
    process_after: Annotated[timedelta, Body()],
    repeat_at: Annotated[time | None, Body()] = None,
):
    start_process = start_datetime + process_after
    duration = end_datetime - start_process
    return {
        "item_id": item_id,
        "start_datetime": start_datetime,
        "end_datetime": end_datetime,
        "process_after": process_after,
        "repeat_at": repeat_at,
        "start_process": start_process,
        "duration": duration,
    }
```

## Related pages

- [About](./about-index.md)
- [Advanced User Guide](./advanced-user-guide-index.md)
- [Deployment](./deployment-index.md)
- [FastAPI](./fastapi-index.md)
- [FastAPI Docs](../index.md)
- [Features](./features-index.md)
- [How To - Recipes](./how-to-recipes-index.md)
- [Learn](./learn-index.md)
- [More](./more-index.md)
- [OpenAPI](./openapi-index.md)

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