I have tried this code

def _get_numbers(self, cr, uid, ids, field_name, arg, context=None):

res = {}

for record in self.browse(cr, uid, ids, context=context):

res[record.id] = record.employee_id

return res

and my field :

'matricules': fields.function(_get_numbers, method=True, string='Total',type='integer'),

But i have got this error TypeError: float() argument must be a string or a number

Please help