关于#翻译器#的问题，如何解决？

这个汉英翻译器的英译汉出了点问题。大家能不能帮我看看？谢谢了！

from tkinter import *
import translate


def han_to_eng():
    global zh_to_en
    if zh_to_en == True:
        zh_to_en = False
        var3.set("英语")
        var4.set("汉语")
        language1, language2 = "zh", "en"
    else:
        zh_to_en = True
        var3.set("汉语")
        var4.set("英语")
        language1, language2 = "en", "zh"
        
tk = Tk()
tk.title("汉英翻译器")

zh_to_en = True
language1 = "en"
language2 = "zh"
var1 = StringVar()
var2 = StringVar()
var3 = StringVar()
var4 = StringVar()
var1.set("")
var2.set("")
var3.set("汉语")
var4.set("英语")

Label(tk, width=50, textvariable=var3).grid(row=0, column=0)
Entry(tk, width=50, textvariable=var1, state=NORMAL).grid(row=1, column=0)
Label(tk, width=50, textvariable=var4).grid(row=0, column=1)
Entry(tk, width=50, textvariable=var2, state=DISABLED).grid(row=1, column=1)
Button(tk, width=50, text="翻译", command=lambda: var2.set(translate.Translator(to_lang=language1, from_lang=language2).translate(var1.get()))).grid(row=2, column=0)
Button(tk, width=50, text="转换", command=han_to_eng).grid(row=2, column=1)

tk.mainloop()

所以有什么问题？我运行没有问题啊。