编写一个程序显示递归树Python，运用tkinter

以下是一个简单的示例程序，可以用递归方式显示二叉树：

import tkinter as tk

class BinaryTree:
    def __init__(self, value):
        self.value = value
        self.left_child = None
        self.right_child = None

    def insert_left(self, value):
        if self.left_child is None:
            self.left_child = BinaryTree(value)
        else:
            new_node = BinaryTree(value)
            new_node.left_child = self.left_child
            self.left_child = new_node

    def insert_right(self, value):
        if self.right_child is None:
            self.right_child = BinaryTree(value)
        else:
            new_node = BinaryTree(value)
            new_node.right_child = self.right_child
            self.right_child = new_node

def draw_tree(canvas, node, x, y, x_offset, y_offset):
    if node is None:
        return

    # Draw node
    canvas.create_oval(x-10, y-10, x+10, y+10, fill='blue')
    canvas.create_text(x, y, text=node.value)

    # Draw left child
    draw_tree(canvas, node.left_child, x-x_offset, y+y_offset, x_offset/2, y_offset)

    # Draw right child
    draw_tree(canvas, node.right_child, x+x_offset, y+y_offset, x_offset/2, y_offset)

if __name__ == '__main__':
    # Create binary tree
    tree = BinaryTree('A')
    tree.insert_left('B')
    tree.insert_right('C')
    tree.left_child.insert_left('D')
    tree.left_child.insert_right('E')
    tree.right_child.insert_left('F')
    tree.right_child.insert_right('G')

    # Create canvas
    root = tk.Tk()
    canvas = tk.Canvas(root, width=600, height=400)
    canvas.pack()

    # Draw tree
    draw_tree(canvas, tree, 300, 50, 200, 50)

    tk.mainloop()

运行程序后，将会显示一个递归树：