iterate example from dataset error

[Ruohan1]

ValueError Traceback (most recent call last)
in ()
----> 1 new_dataset = dataset.map(parse_function)
2 iterator = new_dataset.make_one_shot_iterator()
3 next_element = iterator.get_next()
4
5 sess = tf.InteractiveSession()

/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/data/python/ops/dataset_ops.pyc in map(self, map_func, num_threads, output_buffer_size)
811 A Dataset.
812 """
--> 813 return MapDataset(self, map_func, num_threads, output_buffer_size)
814
815 def flat_map(self, map_func):

/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/data/python/ops/dataset_ops.pyc in init(self, input_dataset, map_func, num_threads, output_buffer_size)
1434
1435 self._map_func = tf_map_func
-> 1436 self._map_func.add_to_graph(ops.get_default_graph())
1437 if num_threads is not None:
1438 self._num_threads = ops.convert_to_tensor(

/usr/local/lib/python2.7/dist-packages/tensorflow/python/framework/function.pyc in add_to_graph(self, g)
617 def add_to_graph(self, g):
618 """Adds this function into the graph g."""
--> 619 self._create_definition_if_needed()
620
621 # pylint: disable=protected-access

/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/data/python/framework/function.pyc in _create_definition_if_needed(self)
165 # Call func and gather the output tensors.
166 with vs.variable_scope("", custom_getter=temp_graph.getvar):
--> 167 outputs = self._func(*inputs)
168 # If func only returned one value, make it a tuple.
169 if not isinstance(outputs, (list, tuple)):

/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/data/python/ops/dataset_ops.pyc in tf_map_func(*args)
1422 ret = map_func(*nested_args)
1423 else:
-> 1424 ret = map_func(nested_args)
1425
1426 # Extract shape information from the returned values.

in parse_function(example_proto)
15 'tensor_shape': tf.FixedLenFeature(shape=(3,), dtype=tf.int64)}
16 # parse all features in a single example according to the dics
---> 17 parsed_example = tf.parse_single_example(example_proto, dics)
18 # decode string
19 parsed_example['tensor'] = tf.decode_raw(parsed_example['tensor'], tf.uint8)

/usr/local/lib/python2.7/dist-packages/tensorflow/python/ops/parsing_ops.pyc in parse_single_example(serialized, features, name, example_names)
742 dense_shapes) = _features_to_raw_params(
743 features,
--> 744 [VarLenFeature, FixedLenFeature, FixedLenSequenceFeature, SparseFeature])
745 outputs = _parse_single_example_raw(
746 serialized, example_names, sparse_keys, sparse_types, dense_keys,

/usr/local/lib/python2.7/dist-packages/tensorflow/python/ops/parsing_ops.pyc in _features_to_raw_params(features, types)
203 raise ValueError("Unsupported VarLenFeature %s.", feature)
204 if not feature.dtype:
--> 205 raise ValueError("Missing type for feature %s." % key)
206 sparse_keys.append(key)
207 sparse_types.append(feature.dtype)

ValueError: Missing type for feature matrix.