1# Copyright 2017 The TensorFlow Authors. All Rights Reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14# ============================================================================== 15"""Helpers constructing Datasets.""" 16from tensorflow.python.framework import constant_op 17from tensorflow.python.framework import dtypes 18from tensorflow.python.framework import ops 19from tensorflow.python.framework import tensor_shape 20 21 22def optional_param_to_tensor(argument_name, 23 argument_value, 24 argument_default=0, 25 argument_dtype=dtypes.int64): 26 if argument_value is not None: 27 return ops.convert_to_tensor( 28 argument_value, dtype=argument_dtype, name=argument_name) 29 else: 30 return constant_op.constant( 31 argument_default, dtype=argument_dtype, name=argument_name) 32 33 34def partial_shape_to_tensor(shape_like): 35 """Returns a `tf.Tensor` that represents the given shape. 36 37 Args: 38 shape_like: A value that can be converted to a `tf.TensorShape` or a 39 `tf.Tensor`. 40 41 Returns: 42 A 1-D `tf.Tensor` of `tf.int64` elements representing the given shape, where 43 `-1` is substituted for any unknown dimensions. 44 """ 45 try: 46 # First attempt to convert the input to a shape, and return the 47 # "canonical" tensor representation, which uses `-1` in place of 48 # `None`. 49 shape_like = tensor_shape.as_shape(shape_like) 50 return ops.convert_to_tensor( 51 [dim if dim is not None else -1 for dim in shape_like.as_list()], 52 dtype=dtypes.int64) 53 except (TypeError, ValueError): 54 # The argument was not trivially convertible to a 55 # `tf.TensorShape`, so fall back on the conversion to tensor 56 # machinery. 57 ret = ops.convert_to_tensor(shape_like, preferred_dtype=dtypes.int64) 58 if ret.shape.dims is not None and len(ret.shape.dims) != 1: 59 raise ValueError("The given shape {} must be a 1-D tensor of `tf.int64` " 60 "values, but the shape was {}.".format( 61 shape_like, ret.shape)) 62 if ret.dtype != dtypes.int64: 63 raise TypeError("The given shape {} must be a 1-D tensor of `tf.int64` " 64 "values, but the element type was {}.".format( 65 shape_like, ret.dtype.name)) 66 67 return ret 68