#### `RequestValidationError`と`ValidationError`

/// warning | 注意

これらは今のあなたにとって重要でない場合は省略しても良い技術的な詳細です。

///

`RequestValidationError`はPydanticの<a href="https://docs.pydantic.dev/latest/concepts/models/#error-handling" class="external-link" target="_blank">`ValidationError`</a>のサブクラスです。

**FastAPI** は`response_model`でPydanticモデルを使用していて、データにエラーがあった場合、ログにエラーが表示されるようにこれを使用しています。

import org.apache.maven.api.di.Singleton;
import org.apache.maven.api.model.Build;
import org.apache.maven.api.model.Model;
import org.apache.maven.api.model.Parent;
import org.apache.maven.api.model.Plugin;
import org.apache.maven.api.model.PluginManagement;
import org.apache.maven.api.model.Repository;
import org.apache.maven.api.model.RepositoryPolicy;
import org.apache.maven.api.services.ModelBuilder;

        fields_to_extract = get_cached_model_fields(first_field.type_)
        single_not_embedded_field = True
        # If headers are in a Pydantic model, the way to disable convert_underscores
        # would be with Header(convert_underscores=False) at the Pydantic model level
        default_convert_underscores = getattr(
            first_field.field_info, "convert_underscores", True
        )

//
//	// CREATE VIEW `user_view` AS SELECT * FROM `users` WHERE age > 20
//	q := DB.Model(&User{}).Where("age > ?", 20)
//	DB.Debug().Migrator().CreateView("user_view", gorm.ViewOption{Query: q})
//
//	// CREATE OR REPLACE VIEW `users_view` AS SELECT * FROM `users` WITH CHECK OPTION
//	q := DB.Model(&User{})

                if annotation_is_pydantic_v1(model):
                    raise PydanticV1NotSupportedError(
                        "pydantic.v1 models are no longer supported by FastAPI."
                        f" In responses={{}}, please update {model}."
                    )
                response_field = create_model_field(
                    name=response_name, type_=model, mode="serialization"
                )

It can't handle nested models very well. So, if the JSON body in the request is a JSON object that has inner fields that in turn are nested JSON objects, it cannot be properly documented and validated.

/// check | Inspired **FastAPI** to

        "//third_party/py/tf_keras/...",
        "//third_party/yggdrasil_decision_forests/...",
        "//waymo/accelerator/...",
        "//waymo/ml/cn/...",
        "//waymo/ml/models/...",
    ],
)

package_group(
    name = "ndarray_tensor_allow_list",
    packages = [
        "//learning/gemini/gemax/...",
        "//third_party/py/courier/...",

This kind of asynchronicity is what made NodeJS popular (even though NodeJS is not parallel) and that's the strength of Go as a programming language.

And that's the same level of performance you get with **FastAPI**.

If your application is **simple**, this will probably **not be a problem**, and you might not need to specify hard memory limits. But if you are **using a lot of memory** (for example with **machine learning** models), you should check how much memory you are consuming and adjust the **number of containers** that runs in **each machine** (and maybe add more machines to your cluster).

from collections.abc import Sequence
from typing import Annotated, Any, Callable, Optional, Union

from annotated_doc import Doc
from fastapi import params
from fastapi._compat import Undefined
from fastapi.openapi.models import Example
from pydantic import AliasChoices, AliasPath
from typing_extensions import Literal, deprecated

_Unset: Any = Undefined


def Path(  # noqa: N802
    default: Annotated[
        Any,
        Doc(