除DataRequired（）外，没有出现任何情况的验证错误

Question

我正在使用wtforms创建注册和登录表单，但是由于某些原因，尽管我认为验证程序正在运行，但错误消息仅在DataRequired（）的文本字段下弹出，而不在Length或EqualTo和我不知道为什么。

我尝试完全转换为导入验证器。我还尝试在验证器函数中填充消息参数，但问题仍然存在。我一直在关注本教程https://www.youtube.com/watch?v=UIJKdCIEXUQ&list=PL-osiE80TeTs4UjLw5MM6OjgkjFeUxCYH&index=3

表格本身

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

class SignUpForm(FlaskForm):
    username = StringField('Username', validators=[DataRequired(), Length(min=4, max=32)])
    password = PasswordField('Password', validators=[DataRequired(), Length(min=6)])
    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('Username taken, please try another.')

class LoginForm(FlaskForm):
    username = StringField('Username', validators=[DataRequired(), Length(min=4, max=32)])
    password = PasswordField('Password', validators=[DataRequired()])
    remember = BooleanField('Remember Me')
    submit = SubmitField('Login')

模板

<div class="form-group">
                    {{ form.password.label(class="form-control-label") }}
                    {% if form.password.errors %}
                        {{ form.password(class="form-control form-control-lg is invalid") }}
                        <div class="invalid-feedback">
                            {% for error in form.password.errors %}
                                <span>{{ error }}</span>
                            {% endfor %}
                        </div>
                    {% else %}
                        {{ form.password(class="form-control form-control-lg") }}
                    {% endif %}
                </div>