@dataclass
class Dependant:
    path_params: List[ModelField] = field(default_factory=list)
    query_params: List[ModelField] = field(default_factory=list)
    header_params: List[ModelField] = field(default_factory=list)
    cookie_params: List[ModelField] = field(default_factory=list)
    body_params: List[ModelField] = field(default_factory=list)
    dependencies: List["Dependant"] = field(default_factory=list)

            )
        self.example = example
        self.include_in_schema = include_in_schema
        self.openapi_examples = openapi_examples
        kwargs = dict(
            default=default,
            default_factory=default_factory,
            alias=alias,
            title=title,
            description=description,
            gt=gt,
            ge=ge,
            lt=lt,
            le=le,
            min_length=min_length,

        item_id: Annotated[int, Path(title="The ID of the item to get")],
    ):
        return {"item_id": item_id}
    ```
    """
    return params.Path(
        default=default,
        default_factory=default_factory,
        alias=alias,
        alias_priority=alias_priority,
        validation_alias=validation_alias,
        serialization_alias=serialization_alias,
        title=title,

}

static TracingContext* CreateTracingExecutionContext(const char* fn_name,
                                                     TF_Status* s) {
  if (default_factory) {
    return default_factory(fn_name, s);
  }
  tsl::Set_TF_Status_from_Status(
      s, errors::FailedPrecondition("default_factory is nullptr"));
  return nullptr;
}

}  // end namespace tracing
}  // end namespace tensorflow

from dataclasses import dataclass, field
from typing import List, Union

from fastapi import FastAPI


@dataclass
class Item:
    name: str
    price: float
    tags: List[str] = field(default_factory=list)
    description: Union[str, None] = None
    tax: Union[float, None] = None


app = FastAPI()


@app.get("/items/next", response_model=Item)
async def read_next_item():
    return {

from pydantic.dataclasses import dataclass  # (2)


@dataclass
class Item:
    name: str
    description: Union[str, None] = None


@dataclass
class Author:
    name: str
    items: List[Item] = field(default_factory=list)  # (3)


app = FastAPI()


@app.post("/authors/{author_id}/items/", response_model=Author)  # (4)
async def create_author_items(author_id: str, items: List[Item]):  # (5)

    * `Path()`
    * `Query()`
    * `Header()`
    * `Cookie()`
    * `Body()`
    * `Form()`
    * `File()`

* The new parameter fields are:

    * `default_factory`
    * `alias_priority`
    * `validation_alias`
    * `serialization_alias`
    * `discriminator`
    * `strict`
    * `multiple_of`
    * `allow_inf_nan`
    * `max_digits`