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"""Miscellaneous utilities that don't fit anywhere else.""" 16 17from __future__ import absolute_import 18from __future__ import division 19from __future__ import print_function 20 21from tensorflow.python.framework import ops 22from tensorflow.python.ops import array_ops 23 24 25def alias_tensors(*args): 26 """Wraps any Tensor arguments with an identity op. 27 28 Any other argument, including Variables, is returned unchanged. 29 30 Args: 31 *args: Any arguments. Must contain at least one element. 32 33 Returns: 34 Same as *args, with Tensor instances replaced as described. 35 36 Raises: 37 ValueError: If args doesn't meet the requirements. 38 """ 39 40 def alias_if_tensor(a): 41 return array_ops.identity(a) if isinstance(a, ops.Tensor) else a 42 43 # TODO(mdan): Recurse into containers? 44 # TODO(mdan): Anything we can do about variables? Fake a scope reuse? 45 if len(args) > 1: 46 return (alias_if_tensor(a) for a in args) 47 elif len(args) == 1: 48 return alias_if_tensor(args[0]) 49 50 raise ValueError('at least one argument required') 51 52 53def capitalize_initial(s): 54 """Capitalizes the initial of a string only.""" 55 if s: 56 return s[0].upper() + s[1:] 57 return s 58