def cat(tensors, dim=0):
"""
Efficient version of torch.cat that avoids a copy if there is only a single element in a list
"""
"""
重写了cat函数,使得当传入的张量只有一个元素的时候避免做拼接操作,只有可拼接的情况下,即有多个元素的情况下进行拼接
"""
assert isinstance(tensors, (list, tuple))
if len(tensors) == 1:
return tensors[0]
return torch.cat(tensors, dim)