import nuke
import nukescripts

class tmpPanel(nukescripts.PythonPanel):

    def __init__(self):

        nukescripts.PythonPanel.__init__(self, "tmp panel")
        self.writes = nuke.Enumeration_Knob("writes", "writes", ["Write1", "Write2"])
        self.render = nuke.PyScript_Knob("render", "render")

        for i in [self.writes, self.render]:
            self.addKnob(i)

    def knobChanged(self, knob):
        if knob is self.render:
            self.renderWrites()

    def renderWrites(self):

        writeNode = self.writes.value()

        nuke.execute(nuke.toNode(writeNode), 1, 5, 1)

tmpPanel().show()