set the 'name' attribute of a django form field

I'm struggling for set the 'name' attribute of a form select field with django.

This is what i'm trying :

def make_layers_form(dxf_model):
layers = Layer.objects.filter(dxf_file=dxf_model)
choices = [(m[0], m[1]) for m in settings.MACHINING_CHOICES]
fields = {}

for l in layers:
    if l.name.decode() == "0":
        # Si le layer 0 existe on l'associe a la "Coupe"
        init = settings.MACHINING_CHOICES["CUT"]
    else:
        # Par défaut on met la valeur "Aucun"
        init = settings.MACHINING_CHOICES["NONE"]

    fields[l.name] = forms.ChoiceField(choices=choices, initial=init, 
                                       widget=fo开发者_高级运维rms.Select(attrs={'name':dxf_model.filename+"_"+str(l.pk)}))


return type('LayersForm', (forms.BaseForm,), {'base_fields':fields})

When I watch to the 'name' attribute, it is not set as expected...

Furthermore I try to set a default value in some case, but it has no effect. Any ideas ?

Thanks for your help!

UPDATE

Here is an html example

 <select name="0" id="3_0">
     <option value="NONE">Aucun</option>
     <option value="CUT">Coupe</option>
     <option value="MARK">Marqueur</option>
 </select>

 ...

 <select name="0" id="4_0">
     <option value="NONE">Aucun</option>
     <option value="CUT">Coupe</option>
     <option value="MARK">Marqueur</option>
 </select>

Each select tag permits to bind some datas to 2 differents files previously uploaded

The value of the attribute 'name' comes from the value of label_tag if I am not wrong.

And the value of the label_tag is a data extracted from each file respectively.

Unfortunately two differents files can contain the same value, which is extracted for setting the attribute 'name'. This is my problem!

So I would define the attribute name of each select tag as it follows: (filename)+"_"+(the value extracted from the file)

I don't know if my explanations are clear...

Do you know why what i'm trying is not working ?

Further more when I set the initial value, it has no effects...