class Car:
    def __init__(self, license_plate, model, color):

        self.license_plate = license_plate
        self.model = model
        self.color = color

    def __str__(self):
        """返回车辆的字符串表示"""
        return f"车牌号: {self.license_plate}, 车型: {self.model}, 颜色: {self.color}"

    def update_info(self, license_plate=None, model=None, color=None):

        if license_plate is not None:
            self.license_plate = license_plate
        if model is not None:
            self.model = model
        if color is not None:
            self.color = color