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Question

我正在尝试修复一些真正意义重大的代码，我试图解决的是删除新的Promise声明并返回初始的Promise，但我正在努力确保我正确地将之前和之后的tanslating。下面我有一个示例，概述了需要更改的场景之一。我错过了前后代码之间的某些内容，还是我正朝着正确的方向前进？另外，对于之后，我是否能够捕获所有被拒绝的错误？

在：

from django.conf.urls import include, url
from django.contrib import admin
from django.conf import settings
from django.conf.urls.static import static

app_name='shop'

urlpatterns = [
    url('admin/', admin.site.urls),
    url(r'^', include('shop.urls', namespace='shop')),
]

if settings.DEBUG:
    urlpatterns += static(settings.MEDIA_URL,
                                document_root=settings.MEDIA_ROOT)

后：

    add(book: IBook, authorId: string): Promise<IBookModel> {
        let p = new Promise((reject, resolve) => {
            let newBook: IBook = new Book({…book});
            newBook.createInitialSetup();
            let bookReady = {... newBook};
            this.bookRepository.add(bookReady)
                .then((completedBook: IBookModel) => {
                    this.bookRepository.findAuthorById(authorId)
                        .then((author: IAuthorModel) => {
                            let newBookAuthor: IAuthorModel = new Author();
                            newBookAuthor(completedBook._id, author._id);

                            let finalBookAuthor = {... newBookAuthor} as IAuthor;

                            this.bookRepository.addBookAuthor(finalBookAuthor)
                                .then((result: IBookAuthorModel) => {
                                    resolve(completedBook);
                                })
                                .catch((err: Error) => {
                                    reject(err);
                                });
                        })
                        .catch((err: Error) => {
                            reject(err);
                        });
                })
                .catch((err: Error) => {
                    reject(err);
                });
        });

        return p;
    }

Answer 1

我错过了前后代码之间的某些内容，还是我正朝着正确的方向前进？

朝着正确的方向旅行。

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也不要嵌套then来电。链then：

add(book: IBook, authorId: string): Promise<IBookModel> {
     let groupSetup: IGroupModel = new Group({...group});
     newBook.createInitialSetup();
     let bookReady = {... newBook};

     return this.bookRepository
                .add(bookReady)
                .then((completedBook: IBookModel) => {
                    return this.bookRepository.findAuthorById(memberId)
                })
                .then(///so on

Answer 2

num_classes = len(np.unique(y_train)) y_train_categorical = keras.utils.to_categorical(y_train, num_classes) kf=StratifiedKFold(n_splits=5, shuffle=True, random_state=999) # splitting data into different folds for i, (train_index, val_index) in enumerate(kf.split(x_train, y_train_categorical)): x_train_kf, x_val_kf = x_train[train_index], x_train[val_index] y_train_kf, y_val_kf = y_train[train_index], y_train[val_index] ValueError: Supported target types are: ('binary', 'multiclass'). Got 'multilabel-indicator' instead.可能会让您的代码更易于理解和阅读：

Async/await

只是几个笔记：

不确定谁async add(book: IBook, authorId: string): Promise<IBookModel> { let newBook: IBook = new Book({ ...book }); newBook.createInitialSetup(); let bookReady = { ...newBook }; let completedBook: IBookModel = await this.bookRepository.add(bookReady) let author: IAuthorModel = await this.bookRepository.findAuthorById(memberId) let newBookAuthor: IAuthorModel = new Author(); newBookAuthor(completedBook._id, author._id); let finalBookAuthor = { ...newBookAuthor } as IAuthor; let result: IBookAuthorModel = await this.bookRepository.addBookAuthor(finalBookAuthor); return completedBook }未在原始代码中定义
您可以使用memberId代码覆盖整个代码，但由于您所做的只是转发错误，因此如果任何等待的承诺失败，则返回的try/catch将被拒绝
带上一粒盐，使用Promise的一般原则是有效的，但转换是在尖叫的婴儿背景下进行的，因此它可能有错误。

Node.js：返回原始Promise与新Promise实例

2 个答案:

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