解决问题
AttributeError: 'MapDataset' object has no attribute 'group_by_window'
解决思路
错误属性：“mapdataset”对象没有“window”的“group”属性
A transformation that groups windows of elements by key and reduces them.
This transformation maps each consecutive element in a dataset to a key using key_func and groups the elements by key. It then applies reduce_func to at most window_size_func(key) elements matching the same key. All except the final window for each key will contain window_size_func(key) elements; the final window may be smaller.
You may provide either a constant window_size or a window size determined by the key through window_size_func.
Args:
key_func: A function mapping a nested structure of tensors (having shapes and types defined by self.output_shapes and self.output_types) to a scalar tf.int64 tensor.
reduce_func: A function mapping a key and a dataset of up to window_size consecutive elements matching that key to another dataset.
window_size: A tf.int64 scalar tf.Tensor, representing the number of consecutive elements matching the same key to combine in a single batch, which will be passed to reduce_func. Mutually exclusive with window_size_func.
window_size_func: A function mapping a key to a tf.int64 scalar tf.Tensor, representing the number of consecutive elements matching the same key to combine in a single batch, which will be passed to reduce_func. Mutually exclusive with window_size.
Returns:
A Dataset transformation function, which can be passed to tf.data.Dataset.apply.
Raises:
ValueError: if neither or both of {window_size, window_size_func} are passed.
解决方法
'MapDataset' 这种对象，没有'group_by_window'这种属性。
tf.contrib.data.group_by_window(
key_func,
reduce_func,
window_size=None,
window_size_func=None
)
# batched_dataset = src_tgt_dataset.group_by_window(
# key_func=key_func, reduce_func=reduce_func, window_size=batch_size)
#20180626修改此处
batched_dataset = src_tgt_dataset.apply(
tf.contrib.data.group_by_window(
key_func=key_func, reduce_func=reduce_func, window_size=batch_size))
