代碼如下所示創(chuàng)建一個(gè)標(biāo)簽和三個(gè)條目小部件，我想使用相同的計(jì)算創(chuàng)建另一個(gè)標(biāo)簽和三個(gè)條目小部件。我正在嘗試添加標(biāo)簽和條目小部件，但不起作用并出現(xiàn)語(yǔ)法錯(cuò)誤。try :    import tkinter as tk # Python 3except :    import Tkinter as tk # Python 2def update_sum() :# Sets the sum of values of e1 and e2 as val of e3    try :        sum_tk.set((float(e1_tk.get().replace(' ', '')) + float(e2_tk.get().replace(' ', ''))))    except :        passroot.after(10, update_sum) # reschedule the eventreturnroot = tk.Tk()root.geometry('850x450')e1_tk = tk.StringVar(root) # Initializes a text variable of tk to use to get e1's val.e2_tk = tk.StringVar(root) # Initializes a text variable of tk to use to get e2's val.sum_tk = tk.StringVar(root) # Initializes a text variable of tk to use to set e3's val.# Entriese1 = tk.Entry(root, textvariable = e1_tk)e1.grid(row=1,column=1)e2 = tk.Entry(root, textvariable = e2_tk)e2.grid(row=1,column=2)e3 = tk.Entry(root, textvariable = sum_tk)e3.grid(row=1,column=3)e4=tk.Label(root,text="SL")e4.grid(row=1,column=0)# Will update the sum every second 10 ms = 0.01 second it takes ms as arg.root.after(10, update_sum)root.mainloop()我想創(chuàng)建另一個(gè)標(biāo)簽，如“SL”和帶有計(jì)算事件的條目小部件