python清空tree.insert()

import tkinter
from tkinter import ttk  # 导入内部包

li = ['王记', '12', '男']
root = tkinter.Tk()
root.title('测试')
tree = ttk.Treeview(root, columns=['1', '2', '3'], show='headings')
tree.column('1', width=100, anchor='center')
tree.column('2', width=100, anchor='center')
tree.column('3', width=100, anchor='center')
tree.heading('1', text='姓名')
tree.heading('2', text='学号')
tree.heading('3', text='性别')
tree.insert('', 'end', values=li)
tree.grid()


def delButton(tree):
    x = tree.get_children()
    for item in x:
        tree.delete(item)


delButton(tree)

root.mainloop()