I have an override of the class ../openerp/addons/base/ir/ir_attachment.py.

I need the id value of the instance in my method overrided _get_path().

My override file contents :

from openerp.osv import osv
import logging
_logger = logging.getLogger(__name__)

class PT_ir_attachment(osv.osv):
    _inherit = 'ir.attachment'
    _name = 'ir.attachment'

    def _get_path(self, cr, uid, bin_data):
        fmonth = "avril-2015"
        fname = 'osot.png'
        fpath = 'dsd'
        test = self._full_path(cr, uid, fname)
        context = {}

       ids = ???? (how could I get instance ID here)

        for attach in self.browse(cr, uid, ids, context=context):
            if attach.store_fname:
                result[attach.id] = self._file_read(cr, uid, attach.store_fname, bin_size)
            else:
                result[attach.id] = attach.db_datas

        _logger.error(self)
        _logger.error(fmonth)
        _logger.error(fname)
        _logger.error(fpath)
        _logger.error(test)
        _logger.error(context)
        _logger.error(uid)
        _logger.error(ids)
        return fname, fpath

Somebody could help please?