def blobproto_to_array(blob):
data = np.array(blob.data)
return data.reshape(blob.num, blob.channels, blob.height, blob.width)
and then for a given layer (that you already have the name of)
layer_name = 'conv1'
weights = blobproto_to_array(net.params[layer_name][0])
and if there are biases,
biases = blobproto_to_array(net.params[layer_name][1])