flask-login

1.配置
login_manager = LoginManager()
login_manager.init_app(app)

例子：
@app.route('/login', methods=['GET', 'POST'])
def login():
# Here we use a class of some kind to represent and validate our
# client-side form data. For example, WTForms is a library that will
# handle this for us, and we use a custom LoginForm to validate.
form = LoginForm()
if form.validate_on_submit():
# Login and validate the user.
# user should be an instance of your User class
login_user(user)

    flask.flash('Logged in successfully.')

    next = flask.request.args.get('next')
    # next_is_valid should check if the user has valid
    # permission to access the `next` url
    if not next_is_valid(next):
        return flask.abort(400)

    return flask.redirect(next or flask.url_for('index'))
return flask.render_template('login.html', form=form)

警告: 你必须验证 next 参数的值。如果不验证的话，你的应用将会受到重定向的攻击。