AssertionError: View function mapping is overwritten an existing endpoint function: home - flask

Question

我正在努力解决http://code.tutsplus.com/tutorials/an-introduction-to-pythons-flask-framework--net-28822

C:\envs\virtalenvs\flask_mini\Scripts\python.exe C:/envs/r2/mini2/intro_to_flask/__init__.py
C:\envs\virtalenvs\flask_mini\lib\site-packages\flask_sqlalchemy\__init__.py:800: UserWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True to suppress this warning.
  warnings.warn('SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True to suppress this warning.')
Traceback (most recent call last):
  File "C:/envs/r2/mini2/intro_to_flask/__init__.py", line 13, in <module>
    from routes import mail
  File "C:\envs\r2\mini2\intro_to_flask\routes.py", line 9, in <module>
    @app.route('/')
  File "C:\envs\virtalenvs\flask_mini\lib\site-packages\flask\app.py", line 1013, in decorator
    self.add_url_rule(rule, endpoint, f, **options)
  File "C:\envs\virtalenvs\flask_mini\lib\site-packages\flask\app.py", line 62, in wrapper_func
    return f(self, *args, **kwargs)
  File "C:\envs\virtalenvs\flask_mini\lib\site-packages\flask\app.py", line 984, in add_url_rule
    'existing endpoint function: %s' % endpoint)
AssertionError: View function mapping is overwriting an existing endpoint function: home

routes.py 文件是：

from intro_to_flask import app
from flask import render_template, request, flash, session, url_for, redirect
from forms import ContactForm, SignupForm, SigninForm
from flask.ext.mail import Message, Mail
from models import db, User

mail = Mail()


@app.route('/')
def home():
    return render_template('home.html')


@app.route('/about')
def about():
    return render_template('about.html')


@app.route('/contact', methods=['GET', 'POST'])
def contact():
    form = ContactForm()

    if request.method == 'POST':
        if form.validate() == False:
            flash('All fields are required.')
            return render_template('contact.html', form=form)
        else:
            msg = Message(form.subject.data, sender='contact@example.com', recipients=['your_email@example.com'])
            msg.body = """
            From: %s <%s>
            %s
            """ % (form.name.data, form.email.data, form.message.data)
            mail.send(msg)

            return render_template('contact.html', success=True)

    elif request.method == 'GET':
        return render_template('contact.html', form=form)


@app.route('/signup', methods=['GET', 'POST'])
def signup():
    form = SignupForm()

    if 'email' in session:
        return redirect(url_for('profile'))

    if request.method == 'POST':
        if form.validate() == False:
            return render_template('signup.html', form=form)
        else:
            newuser = User(form.firstname.data, form.lastname.data, form.email.data, form.password.data)
            db.session.add(newuser)
            db.session.commit()

            session['email'] = newuser.email
            return redirect(url_for('profile'))

    elif request.method == 'GET':
        return render_template('signup.html', form=form)


@app.route('/profile')
def profile():
    if 'email' not in session:
        return redirect(url_for('signin'))

    user = User.query.filter_by(email=session['email']).first()

    if user is None:
        return redirect(url_for('signin'))
    else:
        return render_template('profile.html')


@app.route('/signin', methods=['GET', 'POST'])
def signin():
    form = SigninForm()

    if 'email' in session:
        return redirect(url_for('profile'))

    if request.method == 'POST':
        if form.validate() == False:
            return render_template('signin.html', form=form)
        else:
            session['email'] = form.email.data
            return redirect(url_for('profile'))

    elif request.method == 'GET':
        return render_template('signin.html', form=form)


@app.route('/signout')
def signout():
    if 'email' not in session:
        return redirect(url_for('signin'))

    session.pop('email', None)
    return redirect(url_for('home'))

这可能是什么原因造成的？

编辑：

当我把 about 函数放在首位时，我得到：

 AssertionError: View function mapping is overwriting an existing endpoint function: about

所以我认为问题可能出在导入语句中或至少在第一条路线之前：

from intro_to_flask import app
from flask import render_template, request, flash, session, url_for, redirect
from forms import ContactForm, SignupForm, SigninForm
from flask.ext.mail import Mail, Message
from models import db, User

mail = Mail()

编辑 2：

from flask import Flask

app = Flask(__name__)

app.secret_key = 'development key'

app.config["MAIL_SERVER"] = "smtp.gmail.com"
app.config["MAIL_PORT"] = 465
app.config["MAIL_USE_SSL"] = True
app.config["MAIL_USERNAME"] = 'contact@example.com'
app.config["MAIL_PASSWORD"] = 'your-password'

from routes import mail
mail.init_app(app)

app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://your-username:your-password@localhost/development'

from models import db
db.init_app(app)

import intro_to_flask.routes

Answer 1

这个错误是因为你是循环导入app（你在routes.py中导入app，在app中导入routes.py） 这种模式不起作用，也不正确。 在烧瓶中，您可以在单个文件中编写整个应用程序，也可以使用烧瓶蓝图以模块化方式制作 http://flask.pocoo.org/docs/0.10/blueprints/

您的应用程序可以在单个文件中工作：

from flask import render_template, request, flash, session, url_for, redirect
from forms import ContactForm, SignupForm, SigninForm
from flask.ext.mail import Message, Mail
from models import db, User

from flask import Flask

app = Flask(__name__)

app.secret_key = 'development key'

app.config["MAIL_SERVER"] = "smtp.gmail.com"
app.config["MAIL_PORT"] = 465
app.config["MAIL_USE_SSL"] = True
app.config["MAIL_USERNAME"] = 'contact@example.com'
app.config["MAIL_PASSWORD"] = 'your-password'

mail = Mail()

mail.init_app(app)

app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://your-username:your-password@localhost/development'

from models import db
db.init_app(app)



@app.route('/')
def home():
    return render_template('home.html')


@app.route('/about')
def about():
    return render_template('about.html')


@app.route('/contact', methods=['GET', 'POST'])
def contact():
    form = ContactForm()

    if request.method == 'POST':
        if form.validate() == False:
            flash('All fields are required.')
            return render_template('contact.html', form=form)
        else:
            msg = Message(form.subject.data, sender='contact@example.com', recipients=['your_email@example.com'])
            msg.body = """
            From: %s <%s>
            %s
            """ % (form.name.data, form.email.data, form.message.data)
            mail.send(msg)

            return render_template('contact.html', success=True)

    elif request.method == 'GET':
        return render_template('contact.html', form=form)


@app.route('/signup', methods=['GET', 'POST'])
def signup():
    form = SignupForm()

    if 'email' in session:
        return redirect(url_for('profile'))

    if request.method == 'POST':
        if form.validate() == False:
            return render_template('signup.html', form=form)
        else:
            newuser = User(form.firstname.data, form.lastname.data, form.email.data, form.password.data)
            db.session.add(newuser)
            db.session.commit()

            session['email'] = newuser.email
            return redirect(url_for('profile'))

    elif request.method == 'GET':
        return render_template('signup.html', form=form)


@app.route('/profile')
def profile():
    if 'email' not in session:
        return redirect(url_for('signin'))

    user = User.query.filter_by(email=session['email']).first()

    if user is None:
        return redirect(url_for('signin'))
    else:
        return render_template('profile.html')


@app.route('/signin', methods=['GET', 'POST'])
def signin():
    form = SigninForm()

    if 'email' in session:
        return redirect(url_for('profile'))

    if request.method == 'POST':
        if form.validate() == False:
            return render_template('signin.html', form=form)
        else:
            session['email'] = form.email.data
            return redirect(url_for('profile'))

    elif request.method == 'GET':
        return render_template('signin.html', form=form)


@app.route('/signout')
def signout():
    if 'email' not in session:
        return redirect(url_for('signin'))

    session.pop('email', None)
    return redirect(url_for('home'))

app.run()