theano_backend.py 文件源码

def for_loop(step_function, inputs, initial_hidden_states, go_backwards):
    """
        inputs: time axis must be first
    """ 
    results = theano.scan(
        step_function,
        sequences=inputs,
        outputs_info=initial_hidden_states,
        go_backwards=go_backwards)[0] #screw the updates
    #when results has length 1, it is not returned as a list. wrap it
    if (isinstance(results, list)==False):
        results = [results]
    #put the batch axis back in front
    results = [dimshuffle(tensor, [1,0]+[x for x in xrange(2, tensor.ndim)])
               for tensor in results]
    return results