Question

当我尝试用户验证提交的数据并检查输入的电子邮件是否存在时，我的小注册应用程序会出错并出错。

这是我的档案：
的形式：

from flask.ext.wtf import Form
from wtforms import TextField, BooleanField, PasswordField, TextAreaField, validators
from wtforms.validators import Required
from app import models

class RegisterForm(Form):
"""RegisterForm class needed for retrieving data from user"""
username = TextField('username', [validators.Length(min=3, max=50), validators.Required()])
email = TextField('email', [validators.Length(min=3, max=100), validators.Required()])
password = PasswordField('password', [validators.Required()])
age = TextField('age', [validators.Length(min=1, max=3), validators.Required()])
about_user = TextAreaField('about_user', [validators.Length(max=500)])
img_url = TextField('img_url')


def email_unique(self, email):
    if models.User.query.filter_by(email = email).first() != None:
        self.email.errors.append('This E-mail address is already in use. Please choose another one.') 
        return False

的观点：

#!flask/bin/python
from app import app, db, lm
from flask import render_template, url_for, flash, g, redirect, session, request
from flask.ext.login import login_user, logout_user, current_user, login_required
from forms import LoginForm, RegisterForm, EditForm
from models import User

@app.route('/register', methods = ['GET', 'POST'])
def register():
    form = RegisterForm()
    #makes the username unique
    u_unique =  form.username.data
    u_unique = User.unique_username(u_unique)

    #validates email adress and checks if it already exists or not 
    form.email_unique(form.email.data)

    if form.validate_on_submit():
        user = User(
            u_unique,
            form.password.data, 
            form.email.data, 
            form.age.data, 
            form.about_user.data,
            form.img_url.data)
        db.session.add(user)
        db.session.commit()
        flash('Thank you for your registration')
        flash('Your username is: ' + str(u_unique))
        return redirect(url_for('login'))
    else:
        for error in form.errors:
            flash(error)

    return render_template('register.html',
        title = 'Registeration',
        form = form)

错误是：

Traceback (most recent call last) File <br> "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1701, in __call__ return self.wsgi_app(environ, start_response) 
File "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1689, in wsgi_app response = self.make_response(self.handle_exception(e)) 
File "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1687, in wsgi_app response = self.full_dispatch_request() 
File "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1360, in full_dispatch_request rv = self.handle_user_exception(e) 
File "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1358, in full_dispatch_request rv = self.dispatch_request() 
File "/home/maksad/Desktop/faskMonkey/flask/lib/python2.7/site-packages/flask/app.py", line 1344, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) 
File "/home/maksad/Desktop/faskMonkey/app/views.py", line 92, in register form.email_unique(form.email.data) 
File "/home/maksad/Desktop/faskMonkey/app/forms.py", line 26, in email_unique
 self.email.errors.append('This E-mail address is already in use. Please choose another one.')
 AttributeError: 'tuple' object has no attribute 'append'

Answer 1

tuple个对象cannot append。相反，使用list()转换为列表，然后追加，然后转换回来，如下所示：

>>> obj1 = (6, 1, 2, 6, 3)
>>> obj2 = list(obj1) #Convert to list
>>> obj2.append(8)
>>> print obj2
[6, 1, 2, 6, 3, 8]
>>> obj1 = tuple(obj2) #Convert back to tuple
>>> print obj1
(6, 1, 2, 6, 3, 8)

希望这有帮助！

Answer 2

tuples是不可变类型，这意味着您不能拼接并为它们赋值。如果您要使用需要添加值和删除值的数据类型，请改用list：

>>> a = (1,2,3)
>>> a.append(2)
AttributeError: 'tuple' object has no attribute 'append'
>>> b = [1,2,3]
>>> b.append(2)
[1,2,3,2]

Answer 3

我自己也遇到过这个问题。我认为对你的问题更好的答案是你应该在向它们添加错误之前验证元素。验证过程将错误字段设置为列表，如果在验证字段之前更改它，则在验证时将将其写入。

因此，覆盖表单的validate方法，调用父验证方法，然后在其中运行email_unique方法。

然后您可以从视图中删除email_unique，因为它将成为您的validate_on_submit的一部分

Answer 4

答案更深一些。 Field类创建时，“errors”是一个元组。

class Field(object):
    """
    Field base class
    """
    errors = tuple()

但是当调用方法验证时，它会将其转换为列表

def validate(self, form, extra_validators=tuple()):
    self.errors = list(self.process_errors)

所以你需要的只是在validate_on_submit之后调用你的email_unique函数，而validate_on_submit又调用表单的validate函数并将错误转换为list

@app.route('/register', methods = ['GET', 'POST'])
def register():
    form = RegisterForm()
    #makes the username unique
    u_unique =  form.username.data
    u_unique = User.unique_username(u_unique)

    #validates email adress and checks if it already exists or 

    if form.validate_on_submit():
        form.email_unique(form.email.data)
        user = User(
            u_unique,
            form.password.data, 
            form.email.data, 
            form.age.data, 
            form.about_user.data,
            form.img_url.data)
        db.session.add(user)
        db.session.commit()
        flash('Thank you for your registration')
        flash('Your username is: ' + str(u_unique))
        return redirect(url_for('login'))
    else:
        for error in form.errors:
            flash(error)

    return render_template('register.html',
        title = 'Registeration',
        form = form)

Flask self.errors.append（） - AttributeError：＆＃39; tuple＆＃39;对象没有属性＆＃39;追加＆＃39;

4 个答案: