TypeError:应为字符串或字节，如django中的object.in

当我迁移到模型以下时，它发生了错误，我不明白为什么会发生错误，也不知道如何解决它。

文件"；C： \Users\Ajib\AppData\Local\Programs\Python38\lib\site packages\django\utils\dateparse.py"，第107行，parse_datetime
match=datetime_re.match(值(TypeError：应为字符串或字节，如对象**

在我的模型中：。

models.py
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType
from django.conf import settings
from django.utils.translation import ugettext_lazy as _
from .managers import LikeManager

class Like(models.Model):
"""
"""
user = models.ForeignKey(getattr(settings, 'AUTH_USER_MODEL', 'auth.User'), on_delete=models.CASCADE)
target_content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
target_object_id = models.PositiveIntegerField()
target = GenericForeignKey('target_content_type', 'target_object_id')
timestamp = models.DateTimeField(auto_now_add=True, db_index=True)
objects = LikeManager()
class Meta:
ordering = ["-timestamp"]
get_latest_by = "timestamp"
unique_together = ("user", "target_content_type", "target_object_id")
verbose_name = _("like")
verbose_name_plural = _("likes")
def __unicode__(self):
return u"{} liked {}".format(self.user, self.target)

在我的manager.py文件中

manager.py
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.apps import apps

def _get_content_type_and_obj(obj, model=None):
if isinstance(model, str):
model = apps.get_model(*model.split("."))
if isinstance(obj, (int, int)):
obj = model.objects.get(pk=obj)
return ContentType.objects.get_for_model(type(obj)), obj

class LikeManager(models.Manager):
"""
A Manager for Like objects
"""
from django import VERSION
if VERSION > (1,8):
def get_query_set(self):
return self.get_queryset()
def for_user(self, user, model=None):
"""
Returns a Like objects queryset for a given user.
If a model params is provided, it returns only the
liked objects of that model class
Usage:
Like.objects.for_user(user)
Like.objects.for_user(user, model=Song)
Like.objects.for_user(user, model="music.song")
"""
qs = self.get_query_set().filter(user=user)
if model:
if isinstance(model, str):
model = apps.get_model(*model.split("."))
content_type = ContentType.objects.get_for_model(model)
qs = qs.filter(target_content_type=content_type)
return qs.order_by("-timestamp")
def for_model(self, model):
"""
Returns a Like objects queryset for a given model.
`model` may be a django model class or an string representing
a model in module-notation, ie: "auth.User"
Usage:
Like.objects.for_model(Song)
Like.objects.for_model("music.Song")
"""
# if model is an app_label.model string make it a Model class
if isinstance(model, str):
model = apps.get_model(*model.split("."))
content_type = ContentType.objects.get_for_model(model)
qs = self.get_query_set().filter(
target_content_type=content_type
)
return qs.order_by("-timestamp")
def for_object(self, obj, model=None):
"""
Returns a Like objects queryset for a given object
Usage:
Like.objects.for_object(1, "music.Song")
Like.objects.for_object(1, Song)
or given a music app with a Song model:
song = Song.objects.get(pk=1)
Like.objects.for_object(song)
"""
content_type, obj = _get_content_type_and_obj(obj, model)
qs = self.get_query_set().filter(
target_content_type=content_type,
target_object_id=obj.pk
)
return qs.order_by("-timestamp")
def get_like(self, user, obj, model=None):
"""
Returns a Like instance if the `user` has liked
the given object `obj`. Otherwise returns None
Usage:
Like.objects.get_like(user, 1, "music.Song")
Like.objects.get_like(user, 1, Song)
or given a music app with a Song model:
song = Song.objects.get(pk=1)
Like.objects.get_like(user, song)
"""
content_type, obj = _get_content_type_and_obj(obj, model)
try:
return self.get_query_set().get(
user=user,
target_content_type=content_type,
target_object_id=obj.id
)
except self.model.DoesNotExist:
return None
def create(self, user, obj, model=None):
"""
Creates and returns a new Like obj for the given user and obj
"""
content_type, content_object = _get_content_type_and_obj(obj, model)
like = super(LikeManager, self).create(
user=user,
target_content_type=content_type,
target_object_id=content_object.pk,
target=content_object
)
return like