What is the correct way to set the column percentage of a GridLayout in QT?

Question

Python

Good day.
I am writing a kiosk application in PyQT4. I need to place widgets inside a window.

I need to clearly define the ratios of the two columns of the GridLayout (The one in green in the image).
Solved this by setting the first column to:
grid.setColumnStretch(1,1)
Obviously, this is far from the result I wanted, but it looked good on the surface until I set the long text to the second column in the header. Then the right column stretched beyond the screen borders, which is not acceptable :)
It looks like I met the problem in BoxLyaout in the second column. The vertical Layout should be delimited by approximately the same proportions, for the first time I did the same as with the column
HLayout.setStretchFactor(VLayout,1)
But the solution is temporary, and this is somehow not good. Please explain how to do it right