python - Flask Shell 命令不起作用

Question

我是 python 和 flask 的新手，目前正在研究 Flask Mega-Tutorial ，但是:我一直在获取 flask shell识别我的自定义符号/命令。

当我尝试访问模型时 User通过键入 flask shell 作为符号在我的虚拟环境中，我得到 NameError: name 'User' is not defined .

User应该返回:<class 'application.models.User'> ，而是显示错误。

我不明白的是 app符号似乎工作正常并返回 <Flask 'application'>应该如此。

我在这里做错了什么？进口的东西？

我做了一些研究:this看起来像我的问题，但不使用 app.sell_context_processor装饰器。

我还尝试了我的代码的变体:既改变了从应用程序到应用程序的导入名称，因为我在教程中更改了这些默认值，并使用了user而不是 User (小写与大写)，但似乎没有任何效果。

请帮我解决这个问题!

错误

    (venv) MBP:books mbpp$ flask shell
    Python 3.6.5 (default, Mar 30 2018, 06:42:10) 
    [GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
    App: application
    Instance: /Users/mbpp/Sites/books/instance
    >>> app
    <Flask 'application'>
    >>> User
    Traceback (most recent call last):
      File "<console>", line 1, in <module>
    NameError: name 'User' is not defined

我的代码 来自 application.py

   from application import app, db
   from application.models import User, Book, State, Course, BookTitle, Author

   @app.shell_context_processor
   def make_shell_context():
       return {'db': db, 'User': User, 'State': State, 'BookTitle': BookTitle, 'Author': Author}

来自__init__.py

    from flask import Flask
    from config import Config
    from flask_sqlalchemy import SQLAlchemy
    from flask_migrate import Migrate
    from flask_login import LoginManager

    # initiate the Flask app
    app = Flask(__name__)

    # use the config.py file for configuration
    app.config.from_object(Config)

    # use SQLAlchemy for database management
    db = SQLAlchemy(app)

    # use Flask-Migrate extension for database migration management
    migrate = Migrate(app, db)

    # use Flask-Login extension for login form
    login = LoginManager(app)
    login.login_view = 'login'

    from application import routes, models

来自 models.py(我正在构建一个用户可以卖书的网站)

   from application import db, login
   from datetime import datetime
   from werkzeug.security import generate_password_hash, 
   check_password_hash
   from flask_login import UserMixin

   # create a table to store users
   class User(UserMixin, db.Model):
        id = db.Column(db.Integer, primary_key = True)
        username = db.Column(db.String(64), index = True, unique = True)
        email = db.Column(db.String(120), index = True, unique = True)
        password_hash = db.Column(db.String(128))
        phone = db.Column(db.String(64))
        books = db.relationship('Book', backref='seller_name', lazy='dynamic')

    def __repr__(self):
        return '<User: {}>'.format(self.username)

    # create a password hash
    def set_password(self, password):
        self.password_hash = generate_password_hash(password)

    # check the password hash against a user given password
    def check_password(self, password):
        return check_password_hash(self.password_hash, password)

    # create a table to store information on a book for sale
        class Book(db.Model):
            id = db.Column(db.Integer, primary_key = True)
            course_id = db.Column(db.Integer, db.ForeignKey('course.id'))
            title = db.Column(db.Integer, db.ForeignKey('booktitle.id'))
            author = db.Column(db.Integer, db.ForeignKey('author.id'))
            price = db.Column(db.Integer)
            isbn = db.Column(db.String(64), index = True)
            state_id = db.Column(db.Integer, db.ForeignKey('state.id'))
            state_description = db.Column(db.String(256))
            seller_id = db.Column(db.Integer, db.ForeignKey('user.id'))
            creation_timestamp = db.Column(db.DateTime, index = True, default = datetime.utcnow)

        def __repr__(self):
            return '<Book: {}>'.format(self.title)

    # create a table to store different states books can be in
        class State(db.Model):
            id = db.Column(db.Integer, primary_key = True)
            name = db.Column(db.String(128), index = True)
            books = db.relationship('Book', backref='state', lazy='dynamic')

        def __repr__(self):
            return '<State: {}>'.format(self.name)

    # create a table to store courses
        class Course(db.Model):
            id = db.Column(db.Integer, primary_key = True)
            name = db.Column(db.String(128), index = True)
            year = db.Column(db.Integer, index = True)
            books = db.relationship('Book', backref='course', lazy='dynamic')

        def __repr__(self):
        return '<Course: {}>'.format(self.name)

    # create a table to store booktitles
        class BookTitle(db.Model):
            id = db.Column(db.Integer, primary_key = True)
            title = db.Column(db.String(128), index = True)
            books = db.relationship('Book', backref='book_title', lazy='dynamic')

        def __repr__(self):
           return '<Book title: {}>'.format(self.title)

    # create a table to store authors
        class Author(db.Model):
        id = db.Column(db.Integer, primary_key = True)
        name = db.Column(db.String(128), index = True)
        books = db.relationship('Book', backref='author_name', lazy='dynamic')

        def __repr__(self):
            return '<Author: {}>'.format(self.name)

     # user loader for Flask-Login extension, gets users ID
     @login.user_loader
     def load_user(id):
         return User.query.get(int(id))

Answer 1

非常感谢 Miguel , FLASK Mega Tutorial ( go check that out ) 的作者解决了我的问题!

正如他在 a comment below my question 中指出的那样: 你不能有同名的模块和包。所以不能同时有application文件夹和application.py。

解决方案:

我将我的“application.py”更改为“theapp.py”，现在 flask shell 工作得很好!除了在终端中运行 export FLASK_APP=theapp.py 之外，我不需要更改文件中的任何内容。