python如何写父类

已知有如下几种子类，如何写父类

class MSE(NumpyMetric):
    """Calculates MSE and aggregates by summing across distr processes."""

    def __init__(self, name="MSE", *args, **kwargs):
        super().__init__(name=name, *args, **kwargs)

    def forward(self, gt, pred):
        return mse(gt, pred)


class NMSE(NumpyMetric):
    """Calculates NMSE and aggregates by summing across distr processes."""

    def __init__(self, name="NMSE", *args, **kwargs):
        super().__init__(name=name, *args, **kwargs)

    def forward(self, gt, pred):
        return nmse(gt, pred)


class PSNR(NumpyMetric):
    """Calculates PSNR and aggregates by summing across distr processes."""

    def __init__(self, name="PSNR", *args, **kwargs):
        super().__init__(name=name, *args, **kwargs)

    def forward(self, gt, pred):
        return psnr(gt, pred)


class SSIM(NumpyMetric):
    """Calculates SSIM and aggregates by summing across distr processes."""

    def __init__(self, name="SSIM", *args, **kwargs):
        super().__init__(name=name, *args, **kwargs)

    def forward(self, gt, pred, maxval=None):
        return ssim(gt, pred, maxval=maxval)

class NumpyMetric: #这几个子类都是继承这一个类的 class Child(Parent):
    def __init__(self, name, *args, **kwargs):

这看起来像是是某个模块的源代码

这段代码是要做什么呀 可以请教一下吗