Update frame range from file

def grabFrames(self):
    import os
    plate = self.parm("backplate").eval()
    if not plate:
        framex = self.parm("frange1").eval()
        framey = self.parm("frange2").eval()
    else:
        flist = [x.split(".")[-2] for x in os.listdir(os.path.dirname(plate))]
        fmin = min(flist)
        fmax = max(flist)
        self.parm("frange1").set(int(fmin))
        self.parm("frange2").set(fmax)
        framex = self.parm("frange1").eval()
        framey = self.parm("frange2").eval()
    
    hou.playbar.setFrameRange(framex, framey)
    hou.playbar.setPlaybackRange(framex, framey)