Django的issubclass（）ARG 1必須在管理頁面中insering TabularInline一類錯誤

Question

我在Django有這些模型1.5

class Number(models.Model): 
    number = models.CharField("Patient's Number", max_length=12, unique=True) 
    created = models.DateTimeField("Date created", auto_now=True) 
    created.editable = True 

class Appointment(models.Model): 
    to_number = models.ForeignKey(Number) 
    message = models.CharField("Message", max_length=160) 
    send_on = models.DateTimeField("Date/Time to send the message") 
    email = models.CharField("Email to forward the response to", max_length=254, blank=True) 
    reply_to = models.CharField("Phone number to forward the response to", max_length=12, blank=True) 

    created = models.DateTimeField("Date created", auto_now=True) 
    created.editable = True 

class MyLog(models.Model): 
    to_number = models.CharField("To Number", max_length=12, blank=True) 
    from_number = models.CharField("From Number", max_length=12, blank=True) 
    email = models.CharField("Email to forward the response to", max_length=254, blank=True) 
    message_id = models.CharField("Message ID", max_length=66) 
    message_content = models.CharField("Message Content", max_length=160) 
    message_status = models.CharField("Message status per Twilio", max_length=50) 

    created = models.DateTimeField('Date created', auto_now=True) 
    created.editable = True 

我想看看Appointment爲Number的視圖的一部分（在線） ，所以我遵循Django tutorial part 2，寫這個我admin.py：

from django.contrib import admin 
from sms.models import Number, Appointment, MyLog 

class AppointmentInline(admin.TabularInline): 
    model = Appointment 
    exclude = ('created',) 

class NumberAdmin(admin.ModelAdmin): 
    list_display = ('id', 'number', 'created',) 
    list_display_links = ('id',) 
    list_editable = ('number',) 
    search_fields = ['number'] 
    save_on_top = True 
    readonly_fields = ('created',) 
    inlines = ['AppointmentInline',] # SEEMS LIKE THIS LINE IS CAUSING THE PROBLEM 

class AppointmentAdmin(admin.ModelAdmin): 
    fieldsets = (
     ('Essential Information', { 
      'fields': ('to_number', 'message', 'send_on', 'reply_to', 'email'), 
      'classes': ('wide', 'extrapretty')}), 
     ('Non-Essential Information', { 
      'fields': ('created',), 
      'classes': ('collapse',)}), 
     ) 
    list_display = ('to_number', 'message', 'send_on', 'reply_to', 'email',) 
    list_display_links = ('to_number',) 
    list_editable = ('message', 'send_on', 'reply_to', 'email',) 
    search_fields = ['to_number__number', 'message', 'reply_to', 'email'] 
    save_on_top = True 
    readonly_fields = ('created',) 

class MyLogAdmin(admin.ModelAdmin): 
    list_display = ('to_number', 'from_number', 'email', 'message_content', 'message_status', 'created',) 
    fields = ('to_number', 'from_number', 'email', 'message_content', 'message_status', 'created',) 
    search_fields = ['to_number', 'from_number', 'email', 'message_content', 'message_status'] 
    readonly_fields = ('to_number', 'from_number', 'email', 'message_content', 'message_status', 'created',) 

admin.site.register(Number, NumberAdmin) 
admin.site.register(Appointment, AppointmentAdmin) 
admin.site.register(MyLog, MyLogAdmin) 

但現在我收到以下錯誤，每當我試着通過管理頁面查看Number：

TypeError at /admin/sms/number/ 
... 
Exception Type:  TypeError 
Exception Value:  

issubclass() arg 1 must be a class 

Exception Location:  /home/phyo/.virtualenvs/t4stest/lib/python2.7/site-packages/django/contrib/admin/validation.py in validate, line 179 
Python Executable: /usr/bin/uwsgi 

我是Django的新手，並且在網上搜索了很多東西（谷歌搜索）瞭解我在這裏做錯了什麼，導致了這樣的錯誤。但經過幾個小時的努力，我仍然無法弄清楚這一點。如果有人能幫我解釋我在這裏犯了什麼錯誤，我會非常感激。我的目標是每當通過Django管理頁面查看Number時，都能看到相關的Appointment條目。感謝您的幫助。

Answer 1

內聯不能是一個字符串，即。使用：代替

inlines = [AppointmentInline,] 

：

inlines = ['AppointmentInline',]