[Solved] Pymel UI: is it possible to create UI layouts that can be dynamically resized by the user?

I know the window can be dynamically resized, however I want the user to be able to drag the separator between columns in a row layout so they can choose how much space each column takes up. Think rows/columns in excel, and how the user can manually drag them to decide on the size of each.

EDIT:
Solved, I found another tool that happens to use this, and searched through their code to find it. To anyone else with the same question, what you are looking for is the paneLayout.