Only use relative imports for functions in the same package.

app/auth/forms.py

@@ -1,8 +1,8 @@
+from app.models import User
 from flask_wtf import FlaskForm
 from wtforms import (BooleanField, PasswordField, StringField, SubmitField,
                      ValidationError)
 from wtforms.validators import DataRequired, Email, EqualTo, Length, Regexp
-from ..models import User
 
 
 class LoginForm(FlaskForm):

app/auth/views.py

@@ -1,11 +1,11 @@
+from app import db
+from app.email import send_email
+from app.models import User
 from flask import flash, redirect, render_template, request, url_for
 from flask_login import current_user, login_required, login_user, logout_user
 from . import auth
 from .forms import (LoginForm, PasswordResetForm, PasswordResetRequestForm,
                     RegistrationForm)
-from .. import db
-from ..email import send_email
-from ..models import User
 
 
 @auth.route('/login', methods=['GET', 'POST'])