key: ${{ runner.os }}-python-${{ env.pythonLocation }}-pydantic-v2-${{ hashFiles('pyproject.toml', 'requirements-tests.txt', 'requirements-docs-tests.txt') }}-test-v08
      - name: Install Dependencies
        if: steps.cache.outputs.cache-hit != 'true'
        run: pip install -r requirements-tests.txt
      - name: Install Pydantic v2
        run: pip install "pydantic>=2.0.2,<3.0.0"
      - name: Lint

from fastapi.openapi.models import Example
from pydantic.fields import FieldInfo
from typing_extensions import Annotated, deprecated

from ._compat import PYDANTIC_V2, PYDANTIC_VERSION, Undefined

_Unset: Any = Undefined


class ParamTypes(Enum):
    query = "query"
    header = "header"
    path = "path"
    cookie = "cookie"


class Param(FieldInfo):

```txt
Hello, World from Flask!
```

并且如果您访问 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>，您将会看到由 FastAPI 返回的响应：

```JSON
{
    "message": "Hello World"
}

    """
    class_validators = class_validators or {}
    if PYDANTIC_V2:
        field_info = field_info or FieldInfo(
            annotation=type_, default=default, alias=alias
        )
    else:
        field_info = field_info or FieldInfo()
    kwargs = {"name": name, "field_info": field_info}
    if PYDANTIC_V2:
        kwargs.update({"mode": mode})
    else:
        kwargs.update(
            {

        Optional[str],
        Doc(
            """
            RegEx pattern for strings.
            """
        ),
        deprecated(
            "Deprecated in FastAPI 0.100.0 and Pydantic v2, use `pattern` instead."
        ),
    ] = None,
    discriminator: Annotated[
        Union[str, None],
        Doc(
            """

```txt
Hello, World from Flask!
```

&amp; 🚥 👆 🚶 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> 👆 🔜 👀 📨 ⚪️➡️ FastAPI:

```JSON
{
    "message": "Hello World"
}

!!! info
    These docs are about to be updated. 🎉

    The current version assumes Pydantic v1.

    The new docs will include Pydantic v2 and will use <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a> once it is updated to use Pydantic v2 as well.

!!! warning "Deprecated"
    This tutorial is deprecated and will be removed in a future version.

}
```

!!! info
    In Pydantic v1 the method was called `.dict()`, it was deprecated (but still supported) in Pydantic v2, and renamed to `.model_dump()`.

    The examples here use `.dict()` for compatibility with Pydantic v1, but you should use `.model_dump()` instead if you can use Pydantic v2.

!!! info

from datetime import datetime, timezone
from decimal import Decimal
from enum import Enum
from pathlib import PurePath, PurePosixPath, PureWindowsPath
from typing import Optional

import pytest
from fastapi._compat import PYDANTIC_V2, Undefined
from fastapi.encoders import jsonable_encoder
from pydantic import BaseModel, Field, ValidationError

from .utils import needs_pydanticv1, needs_pydanticv2


class Person:

```txt
Hello, World from Flask!
```

And if you go to <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> you will see the response from FastAPI:

```JSON
{
    "message": "Hello World"
}