python tkinter 获得按钮的文本值

for i in range(3):
    num_frame = tk.Frame(major_frame)
    num_frame.pack()
    for count in range(3*i+1, 3*i+4):
        button = tk.Button(
            num_frame,
            text = count,
            activeforeground = "blue",
            activebackground = "pink",
            width = "13",
            command = lambda : entry.insert("end", count)
        )
        button.grid(row = i, column = count)

import tkinter
class myButton():
    def __init__(self, frame, text, entry, **kwargs):
        side = kwargs.get('side') if 'side' in kwargs else ()
        self.btn = tkinter.Button(
            frame,
            text = text,
            activeforeground="blue",
            activebackground="pink",
            width="13",
            command=lambda :entry.insert("end", text)
        )
        if side:
            self.btn.grid(row=side[0], column=side[1])
        else:
            self.btn.pack()

for i in range(4):
    num_frame = tk.Frame(major_frame)
    num_frame.pack()
    if i < 3:
        for count in range(3*i+1, 3*i+4):
            myButton(num_frame, count, word_entry, side=(i, count))
        continue
    myButton(num_frame, 0, word_entry, side=(i, 0))