change API calls to make them compatible with older TF versions #254 (#…

…260)

* change API calls to make them compatible with older TF versions

* replace 2 more occurences of get_static_value

texar/tf/modules/decoders/dynamic_decode.py

@@ -23,7 +23,7 @@
 
 import tensorflow as tf
 from tensorflow.contrib.seq2seq import Decoder as TFDecoder
-from tensorflow.python.framework import tensor_shape
+from tensorflow.python.framework import tensor_shape, tensor_util
 from tensorflow.python.util import nest
 
 
@@ -55,7 +55,7 @@ def _concat(prefix, suffix, static=False):
     """
     if isinstance(prefix, tf.Tensor):
         p = prefix
-        p_static = tf.get_static_value(prefix)
+        p_static = tensor_util.constant_value(prefix)
         if p.shape.ndims == 0:
             p = tf.expand_dims(p, 0)
         elif p.shape.ndims != 1:
@@ -69,7 +69,7 @@ def _concat(prefix, suffix, static=False):
             if p.is_fully_defined() else None)
     if isinstance(suffix, tf.Tensor):
         s = suffix
-        s_static = tf.get_static_value(suffix)
+        s_static = tensor_util.constant_value(suffix)
         if s.shape.ndims == 0:
             s = tf.expand_dims(s, 0)
         elif s.shape.ndims != 1:
@@ -128,7 +128,7 @@ def _transpose_batch_time(x):
         x transposed along the first two dimensions.
     """
     x_static_shape = x.get_shape()
-    if x_static_shape.rank is not None and x_static_shape.rank < 2:
+    if x_static_shape.ndims is not None and x_static_shape.ndims < 2:
         return x
 
     x_rank = tf.rank(x)
@@ -209,7 +209,7 @@ def _shape(batch_size, from_shape):
                     from_shape.ndims == 0):
                 return None
             else:
-                batch_size = tf.get_static_value(
+                batch_size = tensor_util.constant_value(
                     tf.convert_to_tensor(
                         batch_size, name="batch_size"))
                 return tensor_shape.TensorShape([batch_size]).\