How to use the eccodes.codes_get_size function in eccodes

data = []
        field_names = self._get_abbr_names(subset_nr)
        # print('field_names = ', field_names)
        # print('DEBUG: names = ',self.get_names(subset_nr))
        # print('subset: ', subset_nr)
        
        for field in field_names:
            if field[0] in string.digits:
                print('cannot get data for field: ',field)
                continue
            # print('trying field name: ', field)
            # key = '/subsetNumber={0:d}/{1:s}'.format(subset_nr, field)
            key = field
            # print('trying key: ', key)
            s = eccodes.codes_get_size(self._bufr, key)
            # print('s=', s)
            if s==1:
                value = eccodes.codes_get(self._bufr, key)
                data.append(value)
            else:
                values = eccodes.codes_get_array(self._bufr, key)
                # print('DEBUG: values: ', values)
                data.append(values)

        # finally convert to a numpy array of type object
        # for user convenience
        values = numpy.array(data, dtype='object')

        return values
        #  #]

'code',
            'units',
            'scale',
            'reference',
            'width'
            ]
        
        iterid = eccodes.codes_keys_iterator_new(self._bufr, 'ls')
        while eccodes.codes_keys_iterator_next(iterid):
            keyname = eccodes.codes_keys_iterator_get_name(iterid)
            print('  %s: %s' %
                  (keyname, eccodes.codes_get(self._bufr, keyname)))

        # get unexpanded descriptors
        key = 'unexpandedDescriptors'
        num = eccodes.codes_get_size(self._bufr, key)
        print('  size of %s is: %s' % (key, num))
        values = eccodes.codes_get_array(self._bufr, key)
        for i in xrange(len(values)):
            print("   %d %06d" % (i + 1, values[i]))
        
        # get the expanded descriptors
        key = 'bufrdcExpandedDescriptors'
        num = eccodes.codes_get_size(self._bufr, key)
        print('  size of %s is: %s' % (key, num))
        values = eccodes.codes_get_array(self._bufr, key)
        for i in xrange(len(values)):
            print("   %d %06d" % (i + 1, values[i]))

def get_values(self, descr_nr, autoget_cval=False):
        #  #[
        """
        request an array of values containing the values
        for a given descriptor number for all subsets
        NOTE: this may not work for templates using delayed replication.
        """
        if (self.msg_index == -1):
            raise NoMsgLoadedError

        list_of_names = self._get_abbr_names()
        keyname = list_of_names[descr_nr]
        print('keyname: ', keyname)
        s = eccodes.codes_get_size(self._bufr, keyname)
        t = eccodes.codes_get_native_type(self._bufr, keyname)
        print('key:', keyname, 'size = ', s, 'type = ', t)

        if s==1: # or t==str:
            # values = eccodes.codes_get_string(_bufr, keyname)
            values = [eccodes.codes_get(self._bufr, keyname),]
        else:
            values = eccodes.codes_get_array(self._bufr, keyname)

        return values
        #  #]

while eccodes.codes_keys_iterator_next(iterid):
            keyname = eccodes.codes_keys_iterator_get_name(iterid)
            print('  %s: %s' %
                  (keyname, eccodes.codes_get(self._bufr, keyname)))

        # get unexpanded descriptors
        key = 'unexpandedDescriptors'
        num = eccodes.codes_get_size(self._bufr, key)
        print('  size of %s is: %s' % (key, num))
        values = eccodes.codes_get_array(self._bufr, key)
        for i in xrange(len(values)):
            print("   %d %06d" % (i + 1, values[i]))
        
        # get the expanded descriptors
        key = 'bufrdcExpandedDescriptors'
        num = eccodes.codes_get_size(self._bufr, key)
        print('  size of %s is: %s' % (key, num))
        values = eccodes.codes_get_array(self._bufr, key)
        for i in xrange(len(values)):
            print("   %d %06d" % (i + 1, values[i]))