TypeError: __init__() takes from 1 to 2 positional arguments but 3 were given报错

想要调用

ChamferDist类的__call__函数：

@LOSSES.register_module
class ChamferDist(BaseLoss):
    def __call__(self, pointset1, pointset2):
        '''
        calculate the chamfer distance between two point sets.
        :param pointset1 (B x N x 3): torch.FloatTensor
        :param pointset2 (B x N x 3): torch.FloatTensor
        :return:
        '''
        dist1, dist2 = chamfer_func(pointset1, pointset2)[:2]
        loss = self.weight * ((torch.mean(dist1)) + (torch.mean(dist2)))
        return loss

调用方法：

chamferDistLoss = LOSSES.get('ChamferDist', 'Null')
loss, _ = chamferDistLoss(v, gt_pc)

报错：

TypeError: init() takes from 1 to 2 positional arguments but 3 were given

问题原因和解决方法

调用类的__call__方法，该方法不是静态方法，需要用类的实例来调用，而不能直接用类名调用。
上面的代码第一行得到的是类名，没有加括号得到类的实例，应该改成：

chamferDistLoss = LOSSES.get('ChamferDist', 'Null')()
loss, _ = chamferDistLoss(v, gt_pc)