def openTCLFile(self):
    tf = filedialog.askopenfilename(
        initialdir=os.getcwd() + os.path.join("\\lab_tcl"),
        title="Choose TCL file",
        filetypes=(("TCL Files", "*.tcl"),)
    )
    if tf == "":
        self.tclVar.set("")
        self.chooseTclLabel['text'] = ""
        return

    tf = open(tf)

    self.tclVar.set(tf.name)
    self.chooseTclLabel['text'] = tf.name[tf.name.rfind("/") + 1:len(tf.name)]

    tf.close()