python完成内部函数，使其绘制成三角形(只要代码)

模板代码：
from tkinter import *

def draw_shapes(a_canvas, start_x, start_y, size, number_of_rows):
x_left = start_x
y_down = start_y

root = Tk()
a_canvas = Canvas(root, width=600, height=400)
a_canvas.pack(fill=BOTH, expand = True)
draw_shapes(a_canvas, 20, 30, 50, 6)
a_canvas.mainloop()
接下来怎么写呢

from tkinter import *

def draw_shapes(a_canvas:Canvas, start_x, start_y, size, number_of_rows):
    x_left = start_x
    y_down = start_y    

    for i in range(number_of_rows):
        x = x_left+size*i
        y = y_down
        a_canvas.create_rectangle(x,y,x+size,y+size,fill='blue')
        if i>0:
            x = x_left
            y = y_down+size*i
            a_canvas.create_rectangle(x,y,x+size,y+size,fill='blue')
            for j in range(1, number_of_rows-i):
                x = x_left+size*j
                y = y_down+size*i
                a_canvas.create_oval(x,y,x+size,y+size,fill='blue')
        

root = Tk()
a_canvas = Canvas(root, width=600, height=400)
a_canvas.pack(fill=BOTH, expand = True)
draw_shapes(a_canvas, 20, 30, 50, 6)
a_canvas.mainloop()

您好，我是有问必答小助手，您的问题已经有小伙伴帮您解答，感谢您对有问必答的支持与关注！
PS：问答VIP年卡 【限时加赠：IT技术图书免费领】，了解详情>>> https://vip.csdn.net/askvip?utm_source=1146287632

我的评价是好好考试 别上网让别人帮忙写答案