ManyToMany中的不工作.add（）函数Python3的关系Django

现在我正在用Django中的ManyToManyField设计数据建模。ManyToMany中的不工作.add（）函数Python3的关系Django

我想使每个会话具有各种仪器，

即）

一个有低音。

B有一个鼓。

所以，我测试下一码

from django.test import TestCase 
from Session.models import Instrument 
from Applicants.models import MyUser 
from Session.models import Session 

class InstTest(TestCase): 
    def setUp(self): 
     i1 = Instrument.objects.create(name='bass') 
     i1.save() 
     i2 = Instrument.objects.create(name='guitar') 
     i2.save() 
     i3 = Instrument.objects.create(name='drum') 
     i3.save() 

     u1 = MyUser.objects.create(email='[email protected]', nickname='A') 
     u1.save() 
     u2 = MyUser.objects.create(email='[email protected]', nickname='B') 
     u2.save() 

     s1 = Session.objects.create(players=u1) 
     s1.save() 
     s1.instruments.add(i1) 

     s2 = Session.objects.create(players=u2) 
     s2.save() 
     s2.instruments.create(name='drum') 

    def test_example(self): 
     bass = Instrument.objects.get(name='bass') 
     guitar = Instrument.objects.get(name='guitar') 
     user = MyUser.objects.get(nickname='A') 
     session = Session.objects.get(players=user) 
     self.assertEqual('bass', bass.name) 
     self.assertEqual('A', session.players.nickname) 

     # My problem is in this line 
     self.assertEqual('bass', session.instruments.name)

，这是导致Pycharm

/home/user/vEnv/bin/python /home/user/pycharm-2016.3.2/helpers/pydev/pydevd.py --multiproc --qt-support --client 127.0.0.1 --port 40507 --file /home/user/pycharm-2016.3.2/helpers/pycharm/django_test_manage.py test BandMaker.tests.InstTest.test_example /home/user/PycharmProjects/Project 
Testing started at --:-- PM ... 
warning: Debugger speedups using cython not found. Run '"/home/user/vEnv/bin/python" "/home/user/pycharm-2016.3.2/helpers/pydev/setup_cython.py" build_ext --inplace' to build. 
pydev debugger: process 4984 is connecting 

Connected to pydev debugger (build 163.10154.50) 
Creating test database for alias 'default'... 

Failure 
Traceback (most recent call last): 
    File "/home/user/PycharmProjects/project/BandMaker/tests.py", line 31, in test_example 
    self.assertEqual('bass', player.instruments.name) 
AssertionError: 'bass' != None 

Destroying test database for alias 'default'... 

Process finished with exit code 1

我尝试用其他方式来测试像s1.instruments.create(name='bass')，但我能看到的只是'bass' != None。

我不明白为什么s1.instruments.add(i1)不起作用。所以我需要谁来帮助我。

而且，这里是其他模型类。

/Session/models.py

from django.db import models 
from Applicants.models import MyUser 

# Create your models here. 
class Session(models.Model): 
    players = models.ForeignKey(
     MyUser, 
     verbose_name='own user info', 
     related_name='%(app_label)s_%(class)s_related' 
    ) 

    instruments = models.ManyToManyField(
     'Session.Instrument', 
     verbose_name='Session Instrument List', 
     related_name='%(app_label)s_%(class)s_instruments' 
    ) 

class Instrument(models.Model): 
    name = models.CharField(max_length=50, verbose_name='instrument name')

自定义用户类

from django.db import models 
from django.contrib.auth.models import (
    BaseUserManager, AbstractBaseUser 
) 

class MyUserManager(BaseUserManager): 
    def create_user(self, email, nickname, password=None): 
     """ 
     Creates and saves a User with the given email, date of 
     birth and password. 
     """ 
     if not email: 
      raise ValueError('Users must have an email address') 

     user = self.model(
      email=self.normalize_email(email), 
      nickname=nickname, 
     ) 

     user.set_password(password) 
     user.save(using=self._db) 
     return user 

    def create_superuser(self, email, nickname, password): 
     """ 
     Creates and saves a superuser with the given email, date of 
     birth and password. 
     """ 
     user = self.create_user(
      email=email, 
      password=password, 
      nickname=nickname, 
     ) 
     user.is_admin = True 
     user.save(using=self._db) 
     return user 


class MyUser(AbstractBaseUser): 
    email = models.EmailField(
     verbose_name='email', 
     max_length=255, 
     unique=True, 
    ) 
    nickname = models.CharField(
     verbose_name='nickname', 
     max_length=50, 
     blank=False, 
     unique=False, 
     default='unknown' 
    ) 
    is_active = models.BooleanField(default=True) 
    is_admin = models.BooleanField(default=False) 

    objects = MyUserManager() 

    USERNAME_FIELD = 'email' # When username is required, You must use this field! 
    REQUIRED_FIELDS = ['nickname'] 

    def get_full_name(self): 
     # The user is identified by their email address 
     return self.email 

    def get_short_name(self): 
     # The user is identified by their email address 
     return self.email 

    def __str__(self):    # __unicode__ on Python 2 
     return self.email 

    def has_perm(self, perm, obj=None): 
     "Does the user have a specific permission?" 
     # Simplest possible answer: Yes, always 
     return True 

    def has_module_perms(self, app_label): 
     "Does the user have permissions to view the app `app_label`?" 
     # Simplest possible answer: Yes, always 
     return True 

    @property 
    def is_staff(self): 
     "Is the user a member of staff?" 
     # Simplest possible answer: All admins are staff 
     return self.is_admin

来源

2017-02-19 Irrationnelle