tkinter draw line chart

The author of this article tried to draw a line chart with Canvas during the learning process, but there are many shortcomings. It is better to draw it with matplotlib. The following is the complete code.

import tkinter as tk
import math

Font_SIZE_D = 14
Font_SIZE_L = 14
CANVAS_WIDTH = 500
CANVAS_HEIGHT = 500
DOWN_UNIT = '年份'
LEFT_UNIT = '数量'

# 坐标值
down_v = ['2001', '2002', '2003', '2004', '2005', '2006']
left_v = ['100', '200', '300', '400', '500', '600']

root = tk.Tk()
root.geometry('500x500+300+200')

canvas = tk.Canvas(root, width=CANVAS_WIDTH, height=CANVAS_HEIGHT, bg='yellow')
canvas.pack()

start_x = int(CANVAS_WIDTH * 0.14)
start_y = int(CANVAS_HEIGHT * 0.9)
canvas.create_text(int(start_x * 0.8), int(start_y), text='0', font=('微软雅黑', 14, 'bold'))

down_b = []
left_b = []

# 算出每一格的长度
y = abs(start_y - int(start_y * 0.97))
x = int(start_x * 1.33)

# 取最小
if y >= x:
    v = x
else:
    v = y

# 4段
for i in range(1, len(down_v) + 1):
    # 画横线
    canvas.create_line(start_x * i, start_y, start_x * (i + 1), start_y, width=2)
    canvas.create_line(start_x * (i + 1), start_y, start_x * (i + 1), int(start_y - v), width=2)
    down_b.append(start_x * (i + 1))
    # 写数据
    canvas.create_text(start_x * (i + 1), int(start_y * 1.03), text=down_v[i - 1], font=('微软雅黑', Font_SIZE_D, 'bold'))

    # 画竖线
    canvas.create_line(start_x, start_y - start_x * (i - 1), start_x, start_y - start_x * i, width=2)
    canvas.create_line(start_x, start_y - start_x * i, int(start_x + v), start_y - start_x * i, width=2)
    left_b.append(start_y - start_x * i)

    # 写数据
    canvas.create_text(int(start_x * 0.6), start_y - start_x * i, text=left_v[i - 1],
                       font=('微软雅黑', Font_SIZE_L, 'bold'))

n = [down_b[0], left_b[0]]

#  真值(真实一格距离) 比 虚值(标注的值)
# 给的是标注的值 y
j = abs(int(start_x - n[0])) / 100

# x
h = abs(int(start_x - n[0])) / 1

s = [start_x + int(1 * h), start_y - int(75 * j), start_x + int(2 * h), start_y - int(125 * j), start_x + int(3 * h),
     start_y - int(200 * j), start_x + int(4 * h), start_y - int(300 * j)]

canvas.create_line(*s, width=2, fill='blue')
canvas.create_line(*zip(down_b, left_b), width=2, fill='red')

# 下
canvas.create_line(start_x, start_y, start_x * 7, start_y, width=2)
# 画箭头
canvas.create_line(start_x * 7 - int(start_x * 0.15), start_y - int(start_y * 0.02), start_x * 7, start_y, width=2)
canvas.create_line(start_x * 7 - int(start_x * 0.15), start_y + int(start_y * 0.02), start_x * 7, start_y, width=2)
# 提示
canvas.create_text(start_x * 7 - int(start_x * 0.15), start_y + int(start_y * 0.07), text=LEFT_UNIT, width=2)

# 斜线长度
jian_size = math.pow(
    (start_x * 7 - int(start_x * 0.15) - start_x * 7) ** 2 - (start_y - int(start_y * 0.02) - start_y) ** 2,
    0.5)
deng = math.pow(2, 0.5) * 1.5
# 左
canvas.create_line(start_x, start_y, start_x, start_y - start_x * 6, width=2)
# 画箭头
canvas.create_line(start_x - deng - 5, int((start_y - start_x * 6) + deng + 5), start_x, start_y - start_x * 6,
                   width=2)
canvas.create_line(start_x + deng + 5, int((start_y - start_x * 6) + deng + 5), start_x, start_y - start_x * 6,
                   width=2)
# 提示
canvas.create_text(start_x - 15, start_y - start_x * 6 + 5, text=DOWN_UNIT, width=2)

root.mainloop()