Why can't we use 'for' in GridLayout？

[Jaydar]

If I can't use 'for', how should I draw a grid based on the data?

[ogoffart]

This was just not yet implemented (tracking issue: #358 )

As a workaround, you can either nest horizontal and vertical layout, or do the layouting manually by specifying the x and y properties (like we do in the memory tutorial)