Python keras 模块，engine() 实例源码

def get_batch(X, start=None, stop=None):
    """Like keras.engine.training.slice_X, but supports latent vectors.

    Args:
        X: Numpy array or list of Numpy arrays.
        start: integer, the start of the batch, or a list of integers, the
            indices of each sample in to use in this batch.
        stop: integer, the end of the batch (only needed if start is an
            integer).

    Returns:
        X[start:stop] if X is array-like, or [x[start:stop] for x in X]
        if X is a list. Latent vector functions will be called as appropriate.
    """

    if isinstance(X, list):
        if hasattr(start, '__len__'):
            if hasattr(start, 'shape'):
                start = start.tolist()
            return [x[start] if is_numpy_array(x)
                    else x(len(start)) for x in X]
        else:
            return [x[start:stop] if is_numpy_array(x)
                    else x(stop - start) for x in X]
    else:
        if hasattr(start, '__len__'):
            if hasattr(start, 'shape'):
                start = start.tolist()
            return (X[start] if is_numpy_array(X)
                    else X(len(start)))
        else:
            return (X[start:stop] if is_numpy_array(X)
                    else X(stop - start))