ImportError: cannot import name 'url_decode' from 'werkzeug.urls'

我正在使用 Flask 构建一个网络应用程序。我导入了flask-login库来处理用户登录。但它显示导入错误。

下面是我的文件夹结构：

>flask_blog1
    >flaskblog
        >static
        >templates
        >__init__.py
        >forms.py
        >models.py
        >routes.py
    >instance
        >site.db
    >venv
    >requirements.txt
    >run.py

我的run.py：

from flaskblog import app

if __name__ == "__main__":
    app.run(debug=True)

我的__init__.py：

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_bcrypt import Bcrypt
from flask_login import LoginManager

app = Flask(__name__)
app.config["SECRET_KEY"] = "5791628bb0b13ce0c676dfde280ba245"
app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///site.db"
db = SQLAlchemy(app)
bcrypt = Bcrypt(app)
login_manager = LoginManager(app)

from flaskblog import routes

我的models.py：

from datetime import datetime

# from .extensions import db
from flaskblog import db, login_manager
from flask_login import UserMixin


@login_manager.user_loader
def load_user(user_id):
    return User.query.get(int(user_id))


class User(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(20), unique=True, nullable=False)
    email = db.Column(db.String(120), unique=True, nullable=False)
    image_file = db.Column(db.String(20), nullable=False, default="default.jpg")
    password = db.Column(db.String(60), nullable=False)
    posts = db.relationship("Post", backref="author", lazy=True)

    def __repr__(self):
        return f"User('{self.username}', '{self.email}', '{self.image_file}')"


class Post(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(100), nullable=False)
    date_posted = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)
    content = db.Column(db.Text, nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False)

    def __repr__(self):
        return f"Post('{self.title}', '{self.date_posted}')"

我的routes.py：

from flask import render_template, flash, redirect, url_for
from flaskblog import app, db, bcrypt
from flaskblog.forms import RegistrationForm, LoginForm
from flaskblog.models import User, Post
from flask_login import login_user

posts = [
    {
        "author": "Ashutosh Chapagain",
        "title": "Blog Post 1",
        "content": "First Post Content",
        "date_posted": "October 1, 2023",
    },
    {
        "author": "Ash Dhakal",
        "title": "Blog Post 2",
        "content": "Second Post Content",
        "date_posted": "October 2, 2023",
    },
]


@app.route("/")
@app.route("/home")
def home():
    return render_template("home.html", posts=posts)


@app.route("/about")
def about():
    return render_template("about.html", title="About")


@app.route("/register", methods=["GET", "POST"])
def register():
    form = RegistrationForm()
    if form.validate_on_submit():
        hashed_password = bcrypt.generate_password_hash(form.password.data).decode(
            "utf-8"
        )
        user = User(
            username=form.username.data, email=form.email.data, password=hashed_password
        )
        db.session.add(user)
        db.session.commit()
        flash(f"Your account has been created! You are now able to log in!", "success")
        return redirect(url_for("login"))
    return render_template("register.html", title="Register", form=form)


@app.route("/login", methods=["GET", "POST"])
def login():
    form = LoginForm()
    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
        if user and bcrypt.check_password_hash(user.password, form.password.data):
            login_user(user, remember=form.remember.data)
            return redirect(url_for("home"))
        else:
            flash("Login Unsuccessful. Please check email and password", "danger")
    return render_template("login.html", title="Login", form=form)

我的forms.py：

from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, SubmitField, BooleanField
from wtforms.validators import DataRequired, Length, Email, EqualTo, ValidationError
from flaskblog.models import User


class RegistrationForm(FlaskForm):
    username = StringField(
        "Username", validators=[DataRequired(), Length(min=2, max=20)]
    )
    email = StringField("Email", validators=[DataRequired(), Email()])
    password = PasswordField("Password", validators=[DataRequired()])
    confirm_password = PasswordField(
        "Confirm Password", validators=[DataRequired(), EqualTo("password")]
    )
    submit = SubmitField("Sign Up")

    def validate_username(self, username):
        user = User.query.filter_by(username=username.data).first()
        if user:
            raise ValidationError(
                "That username is taken. Please choose a different one."
            )

    def validate_email(self, email):
        user = User.query.filter_by(email=email.data).first()
        if user:
            raise ValidationError("That email is taken. Please choose a different one.")


class LoginForm(FlaskForm):
    email = StringField("Email", validators=[DataRequired(), Email()])
    password = PasswordField("Password", validators=[DataRequired()])
    remember = BooleanField("Remember Me")
    submit = SubmitField("Login")

确切的错误是：

(venv) asu@asu-Lenovo-Legion-5-15ARH05:/media/asu/Data/Projects/flask_blog1$ python3 run.py
Traceback (most recent call last):
  File "/media/asu/Data/Projects/flask_blog1/run.py", line 1, in <module>
    from flaskblog import app
  File "/media/asu/Data/Projects/flask_blog1/flaskblog/__init__.py", line 4, in <module>
    from flask_login import LoginManager
  File "/media/asu/Data/Projects/flask_blog1/venv/lib/python3.10/site-packages/flask_login/__init__.py", line 12, in <module>
    from .login_manager import LoginManager
  File "/media/asu/Data/Projects/flask_blog1/venv/lib/python3.10/site-packages/flask_login/login_manager.py", line 33, in <module>
    from .utils import _create_identifier
  File "/media/asu/Data/Projects/flask_blog1/venv/lib/python3.10/site-packages/flask_login/utils.py", line 14, in <module>
    from werkzeug.urls import url_decode
ImportError: cannot import name 'url_decode' from 'werkzeug.urls' (/media/asu/Data/Projects/flask_blog1/venv/lib/python3.10/site-packages/werkzeug/urls.py)

我只能假设您获得了 Werkzeug 3.0 更新（因为 Flask-login 没有上绑定其 werkzeug 依赖项）。

在不断删除 werkzeug 的所有非核心公共 API 的过程中，开发人员在Werkzeug 2.3（2023 年 4 月 25 日发布）中弃用了大多数werkzeug.urls，并在 Werkzeug 3.0（2023 年 9 月 30 日发布）中删除了它。

您的选择是：

• 强制werkzeug为 3.0 之前的版本
• 等待 Flask-login 发布与 werkzeug 3 兼容的版本，修复了该问题以及一堆其他内容几分钟前合并

该问题如@Masklinn 所描述。我通过更改requirements.py中的werkzeug和flask的版本并重新安装来解决了这个问题。

我原来的requirements.txt：

bcrypt==4.0.1
blinker==1.6.2
click==8.1.7
dnspython==2.4.2
email-validator==2.0.0.post2
Flask==3.0.0
Flask-Bcrypt==1.0.1
Flask-Login==0.6.2
Flask-SQLAlchemy==3.1.1
Flask-WTF==1.2.0
greenlet==2.0.2
idna==3.4
itsdangerous==2.1.2
Jinja2==3.1.2
MarkupSafe==2.1.3
SQLAlchemy==2.0.21
typing_extensions==4.8.0
Werkzeug==3.0.0
WTForms==3.0.1

我修改后的requirements.txt：

bcrypt==4.0.1
blinker==1.6.2
click==8.1.7
dnspython==2.4.2
email-validator==2.0.0.post2
Flask==2.3.0
Flask-Bcrypt==1.0.1
Flask-Login==0.6.2
Flask-SQLAlchemy==3.1.1
Flask-WTF==1.2.1
greenlet==2.0.2
idna==3.4
itsdangerous==2.1.2
Jinja2==3.1.2
MarkupSafe==2.1.3
SQLAlchemy==2.0.21
typing_extensions==4.8.0
Werkzeug==2.3.0
WTForms==3.0.1

我今天也遇到同样的错误，好像这些功能不再存在了