我试图在Tkinter中创建一个TicTacToe游戏，我试图把一个标签放在棋盘的按钮下，但是当我把标签放在按钮下时，按钮会移动到一边。这是我的代码：

    from tkinter import *
    from tkinter import messagebox
    root = Tk()
    root.title('TicTacToe')
    # X starts
    clicked = True
    count = 0
    #button clicked function
    def b_click(b):
        global clicked
        global count
        
        if b["text"] == " " and clicked == True:
            b["text"] = "X"
            clicked = False
            count += 1
        elif b["text"] == " " and clicked == False:
            b["text"] = "O"
            clicked = True
            count += 1
        else:
            messages["text"] = "you cant do that"
            
    #build the buttons
    b1 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b1))
    b2 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b2))
    b3 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b3))
    b4 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b4))
    b5 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b5))
    b6 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b6))
    b7 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b7))
    b8 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b8))
    b9 = Button(root, text=" ", font =("Helvetica", 20), height=3, width=6, bg="SystemButtonFace", command= lambda:b_click(b9))
    messages  = Label(root, text="", font =("Helvetica", 20), height=1, width=15, relief="sunken")
    space = Label(root, text="", font =("Helvetica",))
    #display the buttons
    b1.grid(row=0, column=0)
    b2.grid(row=0, column=1)
    b3.grid(row=0, column=2)
    
    b4.grid(row=1, column=0)
    b5.grid(row=1, column=1)
    b6.grid(row=1, column=2)
    
    b7.grid(row=2, column=0)
    b8.grid(row=2, column=1)
    b9.grid(row=2, column=2)
    space.grid(row=3, column=0)
    messages.grid(row=4, column=1)
    
    root.mainloop()