self.buttonsFrame = DirectFrame(state= DGG.NORMAL, parent=self)
self.buttonsFrame["state"] = DGG.DISABLED

how do I disable DirectFrame children?

for btn in self.buttonsFrame.getChildren():
    btn.node()["state"] = DGG.DISABLED

this piece of cake raises an error.

thanks in advance!

Unfortunately, due to a limitation of the Python bindings, since getChildren() is a C++ method and DirectFrame a Python class, getChildren() will return the base class NodePath and not a derived Python class like DirectFrame.
You’ll have to store the original DirectFrame children elsewhere.