乙高橋拓士eval函數將字串運算

from tkinter import * #從函式庫 tkinter 輸入所有 * 方法 banks=['摩根大通','美國銀行','中國工商','富國銀行','匯豐銀行','巴黎銀行'] global bank def ABC(): #畫圖 define自訂函數 global b1 #宣告b1是廣域GLOBAL變數,其他函數也可使用 txt = '' for i in range(len(banks)): txt += banks[i] + ' ' b1=Label(canvas,text=txt,font='Arial 20 bold') b1.pack(side=TOP) def XYZ(): #清除視窗的all所有canvas圖 banks.append(bank.get()) ABC()#結束XYZ之前給它顯示 def kill(): banks.pop() ABC() tk = Tk() bank = StringVar(tk) tk.title("高橋拓士python建立tkinter視窗使用者介面") #也可以定義視窗名為 window, root課本都如此習慣 canvas = Canvas(tk, width=400, height=400) canvas.pack() btn1 = Button(tk, text="賴青德銀行", command = ABC, bg='black',fg='white').pack(side=LEFT) btn2 = Button(tk, text="賴青德增加", command = XYZ).pack(side=LEFT) btn3 = Button(tk, text="賴青德刪除", command = kill).pack(side=LEFT) enyry = Entry(tk, textvariable = bank).pack(side=LEFT) tk.mainloop()