我必须检查一个名称是否已经在使用，但要这样做，我必须排除我要编辑的项目

class EditItemForm(forms.ModelForm):

    name = forms.CharField( max_length=80, min_length=3, required=True )

    def clean_name(self):
        # Get the name
        name = self.cleaned_data.get('name')

        if Item.objects.filter(name=name).exclude(id=id).exists(): 
            raise forms.ValidationError('This name is already in use.')

    class Meta:
        model = Item
        fields = ('type', 'name',  )

class Item(models.Model):

    type = models.IntegerField(choices=TYPE, blank=False, default=NO_CAT)
    name = models.CharField(max_length=250 )

    def __str__(self):  #metodo righiesto
        return self.name

如何检索当前项目id/pk以排除它？