缺少1个必需的位置参数:"pk" [英] missing 1 required positional argument: 'pk'

问题描述

我是Django的新手，会做出反应.上周我已经遇到了这个错误，那一次是请求URL错误.昨天我更改了后端设计，现在它的错误再次发生.

I am new in Django and react. I already faced this error at last week and That times its was request URL error. yesterday I changed backend design and now its error happens again.

这是我的网址=>

urlpatterns = [
    url(r'^allowances_mas/', AllowanceAPIView.as_view()),
    url(r'^allowances_mas/(?P<pk>\d+)/$', AllowanceAPIView.as_view()),....

这是我在视图内部的put方法，

here is my put method that inside view,

def put(self,request,pk):
        save_allowance = get_object_or_404(Allowance.objects.all(),pk=pk)
        data = request.data.get('allowance')
        serializer = AllowanceSerializer(instance=save_allowance,data=data,partial=True)

        if serializer.is_valid():           
            allowance_saved=serializer.save()
            return Response({"success":"Allowance '{}' updated successfully".format(allowance_saved.AllowID)})
        else:
            return Response({"fail":"'{}'".format(serializer.errors)})  

这是来自React axios的url请求=>

Here is url request from React axios =>

  axios.put('http://127.0.0.1:8000/api/allowances_mas/1/', { allowance },{
        headers: {
          'Content-Type': 'application/json'
        }
      })
        .then(res => {
          axios.get('http://127.0.0.1:8000/api/allowances_mas/')
          .then(res=>{
            const resallowance=res.data.allowance;  

            this.setState({
              allowances:resallowance 
            });
          })      
        })
        .catch(err=>{
          console.log("error",err);
        })
        .finally(fin=>{
          console.log(fin);
        })

我可以执行get和post方法，但是由于此错误，不能放置和删除.我设置了pk键，为什么它仍然会发生错误?谢谢.

I can do get and post method but put and delete can't because of this error. I set the pk key and why it's still happening the error? Thanks.

推荐答案

发生此错误是因为在put方法中将pk作为参数传递.

The error occurs because you're passing pk as param in put method.

def put(self,request,pk):

相反，请使用:

def put(self, request, *args, **kwargs):

要从传递的网址中获取pk，请使用以下代码:

And for fetching pk from passed URL, use this:

pk = self.kwargs.get('pk')

所以您的代码应如下所示:

So your code should look like this:

def put(self,request, *args, **kwargs):
    pk = self.kwargs.get('pk')
    save_allowance = get_object_or_404(Allowance.objects.all(), pk=pk)
    data = request.data.get('allowance')
    serializer = AllowanceSerializer(instance=save_allowance,data=data,partial=True)

    if serializer.is_valid():           
        allowance_saved=serializer.save()
        return Response({"success":"Allowance '{}' updated successfully".format(allowance_saved.AllowID)})
    else:
        return Response({"fail":"'{}'".format(serializer.errors)})  

此外，更改网址格式的顺序:

Also, change the order of URL patterns:

urlpatterns = [
    url(r'^allowances_mas/(?P<pk>\d+)/$', AllowanceAPIView.as_view()),
    url(r'^allowances_mas/', AllowanceAPIView.as_view()), 
]

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