注册 - 序列项 0：预期的 str 实例，找到 NoneType

Question

Django 版本：3.0.8 - Python 版本：3.7.8我最近在 Django 网站上发现了一个错误。当用户想要创建帐户时，它会返回以下错误：序列项 0：预期的 str 实例，找到 NoneType手术：创建帐户（检查数据库中是否尚不存在用户名）创建用户 Active = False发送一封电子邮件以确认帐户创建。第一步出现错误，创建帐户（Active = False），未发送电子邮件并显示错误。Traceback (most recent call last):  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/core/handlers/exception.py", line 34, in inner    response = get_response(request)  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/core/handlers/base.py", line 115, in _get_response    response = self.process_exception_by_middleware(e, request)  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/core/handlers/base.py", line 113, in _get_response    response = wrapped_callback(request, *callback_args, **callback_kwargs)  File "/home/eodj89/DjangoPro/user/views.py", line 45, in signup    user.save()  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/contrib/auth/base_user.py", line 66, in save    super().save(*args, **kwargs)  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/db/models/base.py", line 746, in save    force_update=force_update, update_fields=update_fields)  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/db/models/base.py", line 795, in save_base    update_fields=update_fields, raw=raw, using=using,  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 175, in send    for receiver in self._live_receivers(sender)  File "/home/eodj89/virtualenv/DjangoPro/3.7/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 175, in <listcomp>    for receiver in self._live_receivers(sender)  File "/home/eodj89/DjangoPro/user/models.py", line 479, in create_user_profile    UserProfile.objects.create(user=instance)

Answer 1

让我简化一下您看到的错误：

In [1]: ''.join([None])

---------------------------------------------------------------------------

TypeError                                 Traceback (most recent call last)

<ipython-input-1-29122f69a077> in <module>

----> 1 ''.join([None])

TypeError: sequence item 0: expected str instance, NoneType found

在您的情况下，您会在这一行得到相同的异常：

address = " ".join([self.full_address])

意思self.full_address就是None.

与此同时，我认为您不需要join那里，因为您尝试连接单个字符串。您对这条线有何期望？

所以你的模型的代码将如下所示：

class Profile(models.Model):

    user = models.OneToOneField(settings.AUTH_USER_MODEL,on_delete=models.CASCADE)

    full_address = models.CharField(null=True,blank=True,max_length=128)

    latitude = models.DecimalField(max_digits=9, decimal_places=6, blank=True, default='0')

    longitude = models.DecimalField(max_digits=9, decimal_places=6, blank=True, default='0')

    slug = models.SlugField(editable=False)

    def save(self, *args,**kwargs):

        self.slug = slugify(self.user.username)

        

        if self.full_address:

            geo_code = geocoder.geocode(self.full_address)

            if geo_code:

                self.longitude = geo_code[0]['geometry']['lng']

                self.latitude  = geo_code[0]['geometry']['lat']

            

        super(Profile, self).save(*args, **kwargs)