I think its due to store= True.

because store=True means it will take value from database.

And In database it will store when you create/Update in existing record.

First try without  store = True

But If you want forcefully store value in database then you should try below.

def _get_stock_move_picking_id( cr, uid, ids, context=None):

        ### logic to return id list of parent object.

def _get_total_quantity(self, cr, uid, ids, field_name, args, context=None):

          #Same logic what ever you done 

         res[stock_move_picking.id] = qty

return res               

'total_quantity':fields.function(total_quantity, method=True,string='tOtal Amount',

                                  store={
                                               'YOUR_LINE_OBJECT': (_get_stock_move_picking_id, ['product_qty'], 20),
                                              }),

Hello ,

your "total_quantity" field also put in stock.picking and check it.

Hi Alcaline,

I find this works for me. v7/v8/v9

import logging

_logger = logging.getLogger('WHATEVER U WANT')

_logger = logging.getLogger(__name__) ## Or FileName of your py.file

_logger.info("Testing: {0}{1}{2}".format(item1, item2, item3))

Now, Im not sure about all your other code, see doc's and check your

Def function & feilds.function are correct.

And test test test... Let us know how you go, & Good luck. 

You define a function field with type float. So, change the following line

res[stock_move_picking.id] = {'total_quantity':qty}

to this one.

res[stock_move_picking.id] = qty

Hi,

Please try this one

res[ids[0]] = qty

return res