Instance partial update

"""
Add this method to a custom form to use as an alternative
to the save method.  When passed an object instance, the it
will set values on the model corresponding to matching
field names on the form.  

Example:

myobject = MyObject.objects.get(pk=1) 
form = MyForm(request.POST) 
    if form.is_valid(): 
        form.update_instance(myobject)
"""
def update_instance(self,instance,commit=True):
    for f in instance._meta.fields:
        if f.attname in self.fields:
            setattr(instance,f.attname,self.cleaned_data[f.attname])
    if commit:
        try: 
            instance.save()
        except: 
            return False
    return instance