def openStudentListFile(self):
    tf = filedialog.askopenfilename(
        initialdir=os.getcwd() + os.path.join("\\studentlists"),
        title="Choose Student List file",
        filetypes=(("Text Files", "*.txt"),)
    )
    if tf == "":
        self.studentListVar.set("")
        self.chooseStudentsLabel['text'] = ""
        return

    tf = open(tf)  # or tf = open(tf, 'r')

    self.studentListVar.set(tf.name)
    self.chooseStudentsLabel['text'] = tf.name[tf.name.rfind("/") + 1:len(tf.name)]
    tf.close()