__init __（）恰恰1個參數（7給出）

Question

所缺乏的我在執行這個錯誤

型號：

class Person(models.Model): 
    last_name = models.CharField(max_length=256) 
    first_name = models.CharField(max_length=256) 

    class Meta: 
     abstract = True 

class Supplier(Person): 

    def __init__(self): 
     super(Supplier, self).__init__() 

class Item(models.Model): 
    name = models.CharField(max_length=256) 
    supplier = models.ForeignKey(Supplier) 
    ... 

def __unicode__(self): 
    return self.name 

瀏覽：

def ItemNew(request): 
    if request.method == "POST": 
     post_item = ItemNewForm(request.POST) 
     ... 
    else: 
     item_form = ItemNewForm() 

     return render(request, "item_new.html", { 
       'item_form' : item_form, 
     }) 

形式：

class ItemNewForm(forms.ModelForm): 
    class Meta: 
     model = Item 

HTML：

... 
<form method="POST" id="item_new_form"> 
{% csrf_token %} 
<label>Name : </label><<span>{{ item_form.name }}</span></span> 
<label>Supplier : </label><span>{{ item_form.supplier }}</span> 
<input type="submit" value="Add"> 
</form> 
... 

回溯：

TypeError at /item/add 
__init__() takes exactly 1 argument (7 given) 
Request Method: GET 
Request URL:  
Django Version: 1.5.4 
Exception Type: TypeError 
Exception Value:  
__init__() takes exactly 1 argument (7 given) 
Exception Location: C:\Python27\lib\site-packages\django\db\models\query.py in iterator, line 327 
Python Executable: C:\Python27\python.exe 
Python Version: 2.7.5 
Python Path:  
['E:\\projects\\WebPOS', 
'E:\\tools\\ide\\eclipse\\plugins\\org.python.pydev_3.0.0.201311051910\\pysrc', 
'E:\\projects\\WebPOS', 
'C:\\Python27\\lib\\site-packages\\distribute-0.6.49-py2.7.egg', 
'C:\\Python27\\DLLs', 
'C:\\Python27\\lib', 
'C:\\Python27\\lib\\lib-tk', 
'C:\\Python27', 
'C:\\Python27\\lib\\site-packages', 
'C:\\Python27\\lib\\site-packages\\setuptools-0.6c11-py2.7.egg-info', 
'C:\\WINDOWS\\SYSTEM32\\python27.zip', 
'C:\\Python27\\lib\\plat-win'] 
Server time: Tue, 10 Dec 2013 07:45:07 +0800 


Error during template rendering: 

In template E:\projects\WebPOS\base\templates\item_new.html, error at line 14 
__init__() takes exactly 1 argument (7 given) 

4 
5 {% block sidebar %} 
6 {% include "nav.html" %} 
7 {% endblock %} 
8 
9 {% block content %} 
10 <h3>Add New Item</h3> 
11 <form method="POST" id="item_new_form"> 
12  {% csrf_token %} 
13  <div class="span-4"><label>Name : </label></div><div class="span-12 last"><span>{{ item_form.name }}</span></div> 
14  <div class="span-4"><label>Supplier : </label></div><div class="span-12 last"><span>{{ item_form.supplier }}</span></div> 
15  <div class="span-16 last"><input type="submit" value="Add"></div> 
16 </form> 
17 {% endblock %} 
18 

Answer 1

的問題是在

class Supplier(Person): 

    def __init__(self): 
     super(Supplier, self).__init__() 

看一看django.db.models.Model source code

class Model(six.with_metaclass(ModelBase)): 
    _deferred = False 

    def __init__(self, *args, **kwargs): 

你__init__功能只得到實例本身作爲參數，但是djang o可能傳遞更多的論據。這就是爲什麼你需要使用*args, **kwargs。

爲了更好地理解*args和**kwargs你可以看看this

Answer 2

通過固定這個錯誤，通過添加參數*args, **kwargs

class Supplier(Person): 

    def __init__(self, *args, **kwargs): 
     super(Supplier, self).__init__(*args, **kwargs) 

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