Flask python app.py不'；t运行，但manage.py runserver运行

我有一个烧瓶应用程序，我正在尝试运行。当我运行python app.py时，似乎有某种循环导入。以下是my models.py和app.py的代码：

型号.py

import datetime
from app import bcrypt, db

class User(BaseModel, db.Model):
    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    email = db.Column(db.String(255), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    registered_on = db.Column(db.DateTime, nullable=False)
    admin = db.Column(db.Boolean, nullable=False, default=False)

    def __init__(self, email, password, admin=False):
        self.email = email
        self.password = bcrypt.generate_password_hash(password)
        self.registered_on = datetime.datetime.now()
        self.admin = admin

from flask import Flask, render_template
from flask import request, jsonify, session
from flask.ext.bcrypt import Bcrypt

from flask_sqlalchemy import SQLAlchemy
from models import User

app = Flask(__name__)
db = SQLAlchemy()

POSTGRES = {
    'user': 'postgres',
    'db': 'postgres',
    'host': 'localhost',
    'port': '5432',
}
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://%(user)s@%(host)s:%(port)s/%(db)s' % POSTGRES
app.config['SECRET_KEY'] = 'lol'

bcrypt = Bcrypt(app)

db.init_app(app)

@app.route('/api/register', methods=['POST'])
def register():
    json_data = request.json
    user = User(
        email=json_data['email'],
        password=json_data['password']
    )
    try:
        db.session.add(user)
        db.session.commit()
        status = 'success'
    except:
        status = 'this user is already registered'
    db.session.close()
    return jsonify({'result': status})

from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
from app import app, db
from models import User

migrate = Migrate(app, db)
manager = Manager(app)

manager.add_command('db', MigrateCommand)

@manager.command
def create_admin():
    """Creates the admin user."""
    db.session.add(User(email='admin@admin.com', password='admin', admin=True))
    db.session.commit()

if __name__ == '__main__':
    manager.run()

app.py

import datetime
from app import bcrypt, db

class User(BaseModel, db.Model):
    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    email = db.Column(db.String(255), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    registered_on = db.Column(db.DateTime, nullable=False)
    admin = db.Column(db.Boolean, nullable=False, default=False)

    def __init__(self, email, password, admin=False):
        self.email = email
        self.password = bcrypt.generate_password_hash(password)
        self.registered_on = datetime.datetime.now()
        self.admin = admin

from flask import Flask, render_template
from flask import request, jsonify, session
from flask.ext.bcrypt import Bcrypt

from flask_sqlalchemy import SQLAlchemy
from models import User

app = Flask(__name__)
db = SQLAlchemy()

POSTGRES = {
    'user': 'postgres',
    'db': 'postgres',
    'host': 'localhost',
    'port': '5432',
}
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://%(user)s@%(host)s:%(port)s/%(db)s' % POSTGRES
app.config['SECRET_KEY'] = 'lol'

bcrypt = Bcrypt(app)

db.init_app(app)

@app.route('/api/register', methods=['POST'])
def register():
    json_data = request.json
    user = User(
        email=json_data['email'],
        password=json_data['password']
    )
    try:
        db.session.add(user)
        db.session.commit()
        status = 'success'
    except:
        status = 'this user is already registered'
    db.session.close()
    return jsonify({'result': status})

from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
from app import app, db
from models import User

migrate = Migrate(app, db)
manager = Manager(app)

manager.add_command('db', MigrateCommand)

@manager.command
def create_admin():
    """Creates the admin user."""
    db.session.add(User(email='admin@admin.com', password='admin', admin=True))
    db.session.commit()

if __name__ == '__main__':
    manager.run()

管理.py

import datetime
from app import bcrypt, db

class User(BaseModel, db.Model):
    __tablename__ = "users"

    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    email = db.Column(db.String(255), unique=True, nullable=False)
    password = db.Column(db.String(255), nullable=False)
    registered_on = db.Column(db.DateTime, nullable=False)
    admin = db.Column(db.Boolean, nullable=False, default=False)

    def __init__(self, email, password, admin=False):
        self.email = email
        self.password = bcrypt.generate_password_hash(password)
        self.registered_on = datetime.datetime.now()
        self.admin = admin

from flask import Flask, render_template
from flask import request, jsonify, session
from flask.ext.bcrypt import Bcrypt

from flask_sqlalchemy import SQLAlchemy
from models import User

app = Flask(__name__)
db = SQLAlchemy()

POSTGRES = {
    'user': 'postgres',
    'db': 'postgres',
    'host': 'localhost',
    'port': '5432',
}
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql://%(user)s@%(host)s:%(port)s/%(db)s' % POSTGRES
app.config['SECRET_KEY'] = 'lol'

bcrypt = Bcrypt(app)

db.init_app(app)

@app.route('/api/register', methods=['POST'])
def register():
    json_data = request.json
    user = User(
        email=json_data['email'],
        password=json_data['password']
    )
    try:
        db.session.add(user)
        db.session.commit()
        status = 'success'
    except:
        status = 'this user is already registered'
    db.session.close()
    return jsonify({'result': status})

from flask_script import Manager
from flask_migrate import Migrate, MigrateCommand
from app import app, db
from models import User

migrate = Migrate(app, db)
manager = Manager(app)

manager.add_command('db', MigrateCommand)

@manager.command
def create_admin():
    """Creates the admin user."""
    db.session.add(User(email='admin@admin.com', password='admin', admin=True))
    db.session.commit()

if __name__ == '__main__':
    manager.run()

我已经尝试过导入，但似乎没有任何效果，我通常会得到如下循环导入错误：

Traceback (most recent call last):
  File "app.py", line 7, in <module>
    from models import User
  File "/Users/Rishub/Desktop/apps/topten/models.py", line 3, in <module>
    from app import bcrypt, db
  File "/Users/Rishub/Desktop/apps/topten/app.py", line 7, in <module>
    from models import User
ImportError: cannot import name User

回溯（最近一次呼叫最后一次）：
文件“app.py”，第7行，在
从模型导入用户
文件“/Users/Rishub/Desktop/apps/topten/models.py”，第3行，在
从应用程序导入bcrypt，db
文件“/Users/Rishub/Desktop/apps/topten/app.py”，第7行，在
从模型导入用户
ImportError:无法导入用户名

有人知道这个问题的解决办法吗？

---

此外，如果我运行python manage.py runserver，我的应用程序运行得很好，因此我很想知道为什么这样做有效，而python app.py却不行。

在models.py中，您正在导入：

from app import bcrypt, db

在app.py中，您正在导入模型

from models import User

要修复它，请按如下所示重新构造程序：

使用数据库配置等创建database.py文件

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('sqlite:////tmp/test.db', convert_unicode=True)
db_session = scoped_session(sessionmaker(autocommit=False,
                                         autoflush=False,
                                         bind=engine))
Base = declarative_base()
Base.query = db_session.query_property()

def init_db():
    import models
    Base.metadata.create_all(bind=engine)

在models.py中将其用作

from database import Base
from sqlalchemy import Column, Integer, String

# instead of db.column directly use Column

class User(Base):

和应用程序文件，如下所示：

from database import init_db
init_db()
from database import db_session
from models import User

@app.route('/api/register', methods=['POST'])
def register():
    json_data = request.json
    user = User(
        email=json_data['email'],
        password=json_data['password']
    )
    db_session.add(user)
    db_session.commit()
    return jsonify({'result': 'success'})

---

共享

manage.py

代码，这样我们就可以知道它是如何运行的，而不是

app.py

。我猜manage.py没有连接到app.py，因此它正在工作。只是添加了manage.py我不知道你的manage.py是如何工作的。但是您需要按照我共享的链接所说的那样重新构造代码。这样做，app.py就会得到修复。你能回答我下面的问题吗？thanksPython app.py不工作，因为您不运行实例，就像manager一样，您需要调用实例的run（）方法。尝试在app.py的末尾添加app.run（）：我有一个类BaseModel（db.Model）：但是如果没有db，我该怎么做？添加了应该用于

类用户（Base）的代码片段：

是否没有像“app=Flask（name）”这样的实际应用实例？我仍然很困惑如何像上面那样使用bcrypt你仍然可以使用它，对吗<代码>应用程序=烧瓶（\uuuuu名称）

bcrypt=bcrypt（应用程序）

。这样做有什么不对？