(cells, inputs, dilations)
return x
This function constucts a multi-layer dilated RNN. 
    Inputs:
        cells -- A list of RNN cells.
        inputs -- A list of 'n_steps' tensors, each has shape (batch_size, input_dims).
        dilations -- A list of integers with the same length of 'cells' indicates the dilations for each layer.
    Outputs:
        x -- A list of 'n_steps' tensors, as the outputs for the top layer of the multi-dRNN.
This function constucts a multi-layer dilated RNN. 
    Inputs:
        cells -- A list of RNN cells.
        inputs -- A list of 'n_steps' tensors, each has shape (batch_size, input_dims).
        dilations -- A list of integers with the same length of 'cells' indicates the dilations for each layer.
    Outputs:
        x -- A list of 'n_steps' tensors, as the outputs for the top layer of the multi-dRNN.
This function constucts a multi - layer dilated RNN . Inputs : cells -- A list of RNN cells . inputs -- A list of n_steps tensors each has shape ( batch_size input_dims ) . dilations -- A list of integers with the same length of cells indicates the dilations for each layer . Outputs : x -- A list of n_steps tensors as the outputs for the top layer of the multi - dRNN .
def multi_dRNN_with_dilations(cells, inputs, dilations):
    """
    This function constucts a multi-layer dilated RNN. 
    Inputs:
        cells -- A list of RNN cells.
        inputs -- A list of 'n_steps' tensors, each has shape (batch_size, input_dims).
        dilations -- A list of integers with the same length of 'cells' indicates the dilations for each layer.
    Outputs:
        x -- A list of 'n_steps' tensors, as the outputs for the top layer of the multi-dRNN.
    """
    assert (len(cells) == len(dilations))
    x = copy.copy(inputs)
    for cell, dilation in zip(cells, dilations):
        scope_name = "multi_dRNN_dilation_%d" % dilation
        x = dRNN(cell, x, dilation, scope=scope_name)
    return x
def multi_dRNN_with_dilations ( cells , inputs , dilations ) : assert ( len ( cells ) == len ( dilations ) ) x = copy . copy ( inputs ) for cell , dilation in zip ( cells , dilations ) : scope_name = "multi_dRNN_dilation_%d" % dilation x = dRNN ( cell , x , dilation , scope = scope_name ) return x