擅长:python、mysql、java
<p>因为num总是43岁</p>
<pre><code>import tkinter as tk
num = 42
def increase():
global num
num += 1
lbl1.configure(text = str(num))
panel = tk.Tk()
lbl1 = tk.Label(panel, text = str(num))
lbl1.pack()
btn = tk.Button(panel, text = 'Increase', command = increase)
btn.pack()
panel.mainloop()
</code></pre>