XXX received an invalid combination of arguments - got (axis=NoneType, dtype=NoneType

**TypeError: mean() received an invalid combination of arguments - got (axis=NoneType, dtype=NoneType, out=NoneType, ), but expected one of:

• (*, torch.dtype dtype)
• (tuple of names dim, bool keepdim, *, torch.dtype dtype)
• (tuple of ints dim, bool keepdim, , torch.dtype dtype)*

mean()还有可能是min(),sum(),std(),where()等等
上述粗体的错误是torch与numpy之间的区别导致的，将 np.sun()改成torch.sum()即可。
按照错误提示修改。