skeletalWindow.py

from mGui.gui import *
# note the caps: all of these are wrapper objects, not maya.cmds!

window = Window('main window', title="How's this")  
with ColumnLayout('gui', width = 256) as gui:
    with FrameLayout("t_buttons", label = "buttons column"):
        with ColumnLayout("col"):
            Button('mkSphere', label = "Make Sphere")
            Button('mkCone', label ="Make Cone")
            Button('mkCube', label ="Make Cube")
       
    with FrameLayout("r_buttons", label = "buttons row"):
        with RowLayout ("row", numberOfColumns=3):
            Button('mkSphere', label = "Make Sphere")
            Button('mkCone', label ="Make Cone")
            Button('mkCube', label ="Make Cube")

    with FrameLayout("g_buttons", label = "buttons grid"):
        with GridLayout("grid", numberOfColumns = 2):
            Button('mkSphere', label = "Make Sphere")
            Button('mkCone', label ="Make Cone")
            Button('mkCube', label ="Make Cube")
            Button('mkCircle', label = "Make Circle")