[PyQt] Whitespaces inside table widget

[disconnext]

I have a QTableWidget in layout. And I want it to change it's size with
the addition of a new row, leaving no whitespaces inside table widget.
(Row added, layout cell expanded.)

        posLayout = QVBoxLayout()
        posLayout.addWidget(posTitle)
        posLayout.addWidget(posTable)
        posLayout.addWidget(posTotal)
  ?     posLayout.addStretch()

Layout itself has a height not affected by the table. So when the
stretch -> 0, the scrollbar appears instead of table expansion.

Is there any "right way" to make it work?
Or how can I calculate the my desired table size without whitespaces?

disconnext