Python经典编程习题100例：第57例：画图，学用line画直线

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canvas = Canvas(width=300, height=300, bg='green')   
    canvas.pack(expand=YES, fill=BOTH)                  
    x0 = 263
    y0 = 263
    y1 = 275
    x1 = 275
    for i in range(19):
        canvas.create_line(x0,y0,x0,y1, width=1, fill='red')
        x0 = x0 - 5
        y0 = y0 - 5
        x1 = x1 + 5
        y1 = y1 + 5
    x0 = 263
    y1 = 275
    y0 = 263
    for i in range(21):
        canvas.create_line(x0,y0,x0,y1,fill = 'red')
        x0 += 5
        y0 += 5
        y1 += 5
    mainloop()