错误：ImportError：无法导入名称LoginForm

Question

I am facing import error while importing LoginForm

import form

This import imports perfectly. But when I do

from form import LoginForm

Traceback (most recent call last):
File "<pyshell#2>", line 1, in <module>
from form import LoginForm
ImportError: cannot import name LoginForm

Also When I import form only and try to use LoginForm it gives me error

NameError: global name 'LoginForm' is not defined

Please let me know the problem

Thanks in advance Abhishek

Answer 1

Do you have a file in your directory called form.py? Or is this file itself called form.py? If so, python could be loading that instead. Especially if you are using 2.7,where relative imports are prioritized.

Try printing

print(form._ file _) (Double underscore before and after file)

to see where the module is. Or printing

dir(form)

to see what is in the namespace

Answer 2

Your import statement is fine.

If form is a file in your directory, you need to post its content. Most likely it's missing the definition for a LoginForm class.

See this tutorial from miguel to show an example:

http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-iii-web-forms

Let's write our first form (file app/forms.py):

from flask.ext.wtf import Form 
from wtforms import StringField, BooleanField 
from wtforms.validators import DataRequired 

class LoginForm(Form): 
    openid = StringField('openid',  validators=[DataRequired()]) 
    remember_me = BooleanField('remember_me', default=False)