需要3到5个位置参数，但给出了6个？

我的程序应该使用用户输入来绘制棋盘。绘图必须通过调用draw（）来进行。我收到一个错误：

line 18, in main
 chessboard = Chessboard(tr, startX, startY, eval(width),  val(height)) 
TypeError: __init__() takes from 3 to 5 positional arguments but 6 were given

问题是我的主模块无法更改。我必须保持原样。这是一个要求。那么，当我不能改变一个问题时，我该如何解决呢？它只会在第18行给我一个错误。

主模块：

import turtle
from chessboard import Chessboard

def main():
    startX, startY = eval(input("Enter a starting point: "))
    width = input("Input a width: ")
    height = input("Input a height: ")

    tr = turtle.Turtle()

    if width == "" and height == "":
        chessboard = Chessboard(tr, startX, startY)
    elif height == "":
        chessboard = Chessboard(tr, startX, startY, width=eval(width))
    elif width == "":
        chessboard = Chessboard(tr, startX, startY, height=eval(height))
    else:
        chessboard = Chessboard(tr, startX, startY, eval(width), eval(height))

        chessboard.draw()

        tr.hideturtle()
        turtle.done()

main()

我离开了Chessboard.py模块，以防它需要做一些事情：

import turtle


class Chessboard:
    def __init__(self, startX, startY, width=250, height=250):
        self.__startX = startX
        self.__startY = startY
        self.__width = width
        self.__height = height

    def draw(self, __startX, __startY, __width=250, __height=250):
        turtle.clear
        self.__drawChessboard(__startX, __startY, __width, __height)

    def __drawChessboard(self, __startX, __startY, __width=250, __height=250):
        # uses height x width, default 250
        turtle.setheading(0)  
        turtle.penup() 
        turtle.goto(__startX, __startY) 
        turtle.pendown() 
        turtle.goto(__startX + __width, __startY)
        turtle.goto(__startX + __width, __startY + __height)
        turtle.goto(__startX, __startY + __height)
        turtle.goto(__startX, __startY)

        self.__drawAllRectangles(self, __startX, __startY, __width, __height)

        turtle.exitonclick()

    def __drawAllRectangles(self, __startX, __startY, __width, __height):
        __checkerWidth = __width / 8
        __checkerHeight = __height / 8
        for row in range(8):
            for column in range(4):
                if row % 2 == 0:
                    self.__drawRectangle(self, __startX + (2 * column * __checkerWidth),
                                         __startY + (row * __checkerHeight), __checkerWidth, __checkerHeight)
                else:
                    self.__drawRectangle(self, __startX + __checkerWidth + (2 * column * __checkerWidth),
                                         __startY + (row * __checkerHeight), __checkerWidth, __checkerHeight)

    def __drawRectangle(self, __startX, __startY, __checkerWidth, __checkerHeight):
        turtle.penup()
        turtle.setheading(0)
        turtle.goto(__startX, __startY)
        turtle.fillcolor("black")
        turtle.begin_fill()
        turtle.pendown()
        turtle.goto(__startX + __checkerWidth, __startY)
        turtle.goto(__startX + __checkerWidth, __startY + __checkerHeight)
        turtle.goto(__startX, __startY + __checkerHeight)
        turtle.goto(__startX, __startY)
        turtle.end_fill()

谢谢你的帮助！