Hi @jmandivarapu1
Based on what I understand, method Tensor.fill_(val) intends to let you fill tensors with a certain value, just like numpy.zeros() (I’m not totally sure about this). But in your example,  net.conv1.weight[0].data.fill_(1.0) will certainly fill net.conv1.weight[0] with all 1.
To modify the weight of your model partially or fully, load_state_dict should do the trick for you:
http://pytorch.org/docs/master/nn.html?highlight=load_state_dict#torch.nn.Module.load_state_dict 45