Project 2 (Move Fast with FastAPI), HTTP Exceptions

코드

from typing import Optional
from fastapi import FastAPI, HTTPException, Request
from pydantic import BaseModel, Field
from uuid import UUID
from starlette.responses import JSONResponse

class NegativeNumberException(Exception):
    def __init__(self, books_to_return):
        self.books_to_return = books_to_return


app = FastAPI()


class Book(BaseModel):
    id: UUID
    title: str = Field(min_length=1)
    author: str = Field(min_length=1, max_length=100)
    description: Optional[str] = Field(title='Description of the book',
                             max_length=100,
                             min_length=1)
    rating: int = Field(gt=-1, lt=101)

    class Config:
        schema_extra = {
            'example': {
                'id': "8a359f37-75fb-49c3-a7b7-d49a813b9ca2",
                'title': 'Computer Science Pro',
                'author': 'Coding with Hansol',
                'description': 'A very nice description of a book',
                'rating': 75
            }
        }

BOOKS = []

@app.exception_handler(NegativeNumberException)
async def negative_number_exception_handler(request: Request,
                                            exception: NegativeNumberException):
    return JSONResponse(
        status_code=418,
        content={'message': f'hey, why do want {exception.books_to_return}'
                 f'books? you need to read more!'}
    )


@app.get('/')
async def read_all_books(books_to_return: Optional[int] = None):

    if books_to_return and books_to_return < 0:
        raise NegativeNumberException(books_to_return=books_to_return)

    if len(BOOKS) < 1:
        create_books_no_api()

    if books_to_return and len(BOOKS) >= books_to_return > 0:
        i = 1
        new_books = []
        while i <= books_to_return:
            new_books.append(BOOKS[i -1])
            i += 1
        return new_books
    return BOOKS

@app.get('/book/{book_id}')
async def read_book(book_id:UUID):
    for x in BOOKS:
        if x.id == book_id:
            return x
    raise_item_cannot_be_found_exception()


@app.post('/')
async def create_book(book: Book):
    BOOKS.append(book)
    return book

@app.put('/{book_id}')
async def update_book(book_id: UUID, book:Book):
    counter = 0

    for x in BOOKS:
        counter += 1
        if x.id == book_id:
            BOOKS[counter - 1] = book
            return BOOKS[counter - 1]
    raise raise_item_cannot_be_found_exception()

@app.delete('/{book_id}')
async def delete_book(book_id: UUID):
    counter = 0

    for x in BOOKS:
        counter += 1
        if x.id == book_id:
            del BOOKS[counter -1]
            return f'ID:{book_id} deleted'
    raise raise_item_cannot_be_found_exception()

'''   
    raise HTTPException(status_code=404, detail = 'Book not found',
                        headers={'X-Heasder-Error':
                                 'Nothing to be seen at the UUID'})
'''

def create_books_no_api():
    book_1 = Book(id='9a359f37-75fb-49c3-a7b7-d49a813b9ca2',
                    title='Title 1',
                    author='Author 1',
                    description='Description 1',
                    rating=60)
    book_2 = Book(id='2a359f37-75fb-49c3-a7b7-d49a813b9ca2',
                    title='Title 2',
                    author='Author 2',
                    description='Description 2',
                    rating=70)
    book_3 = Book(id='3a359f37-75fb-49c3-a7b7-d49a813b9ca2',
                     title='Title 3',
                     author='Author 3',
                     description='Description 3',
                     rating=80)
    book_4 = Book(id='4a359f37-75fb-49c3-a7b7-d49a813b9ca2',
                    title='Title 4',
                    author='Author 4',
                    description='Description 4',
                    rating=90)
    BOOKS.append(book_1)
    BOOKS.append(book_2)
    BOOKS.append(book_3)
    BOOKS.append(book_4)


def raise_item_cannot_be_found_exception():
    return HTTPException(status_code=404,
                         detail='Book not found',
                         headers={'X-Header-Error':
                                  'Nothing to be seen at the UUID'})