python应用程序上的循环导入

我开始学习python和，但我在理解作者如何布置文件方面遇到了一些困难。据我所知，我似乎遇到了一个循环导入问题，我无法解决它

文件设置如下：

\uuuu init\uuuuu.py

from flask import Flask
app = Flask(__name__)

app.config['SECRET_KEY'] = "something here";
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite://app.db"

from flask import render_template, request, redirect, url_for, abort, session
from app import app

@app.route('/')
.... some stuff here

from flask.ext.sqlalchemy import SQLAlchemy
from app import app

db = SQLAlchemy(app)

class User(db.Model):
.... some stuff here

#!/usr/bin/env python
from flask.ext.script import Manage, Shell, Server 
from app import app

manage = Manager(app)
manager.add_command("runserver", Server())
manager.add_command("shell", Shell())

@manager.command
def createdb():
   from app.models import db
   db.create_all()

manager.run()

app.py

from flask import Flask
app = Flask(__name__)

app.config['SECRET_KEY'] = "something here";
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite://app.db"

from flask import render_template, request, redirect, url_for, abort, session
from app import app

@app.route('/')
.... some stuff here

from flask.ext.sqlalchemy import SQLAlchemy
from app import app

db = SQLAlchemy(app)

class User(db.Model):
.... some stuff here

#!/usr/bin/env python
from flask.ext.script import Manage, Shell, Server 
from app import app

manage = Manager(app)
manager.add_command("runserver", Server())
manager.add_command("shell", Shell())

@manager.command
def createdb():
   from app.models import db
   db.create_all()

manager.run()

models.py

from flask import Flask
app = Flask(__name__)

app.config['SECRET_KEY'] = "something here";
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite://app.db"

from flask import render_template, request, redirect, url_for, abort, session
from app import app

@app.route('/')
.... some stuff here

from flask.ext.sqlalchemy import SQLAlchemy
from app import app

db = SQLAlchemy(app)

class User(db.Model):
.... some stuff here

#!/usr/bin/env python
from flask.ext.script import Manage, Shell, Server 
from app import app

manage = Manager(app)
manager.add_command("runserver", Server())
manager.add_command("shell", Shell())

@manager.command
def createdb():
   from app.models import db
   db.create_all()

manager.run()

manage.py

from flask import Flask
app = Flask(__name__)

app.config['SECRET_KEY'] = "something here";
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite://app.db"

from flask import render_template, request, redirect, url_for, abort, session
from app import app

@app.route('/')
.... some stuff here

from flask.ext.sqlalchemy import SQLAlchemy
from app import app

db = SQLAlchemy(app)

class User(db.Model):
.... some stuff here

#!/usr/bin/env python
from flask.ext.script import Manage, Shell, Server 
from app import app

manage = Manager(app)
manager.add_command("runserver", Server())
manager.add_command("shell", Shell())

@manager.command
def createdb():
   from app.models import db
   db.create_all()

manager.run()

第一个错误是无法通过运行manage.py runserver启动服务器。最初我可以这样做，直到我在init.py中切换文件初始化应用程序（最初我将所有内容都放在app.py中）。我收到一个错误，上面写着——

ImportError:无法导入名称应用程序

除此之外，如果我删除init.py并让服务器启动并运行，我将无法创建数据库，因为我收到一个错误，说明-

---

导入错误：运行manage.py createdb时没有名为models的模块

，

您试图从app导入app，从app导入app？…这与目录的命名方式有关吗？我的父文件夹名为“app”，而在本教程中，父文件夹名为“example”，并使用“from example import app”，这就是为什么我将其写为“from app import app”

from x import y

means。您的init文件实际上被准确地称为

init.py

？它应该是

\uuuu init\uuuu.py

。它的目的是将目录转换为包。您通常不会在其中放入太多/任何代码。是的，它名为init。所以从app导入app意味着从app.py文件导入app（烧瓶对象）？是的，但它本身并不意味着什么。将

init.py

文件重命名为

\uuuuu init\uuuuuu.py

，再次通读本教程并通读