Change internal constant RESERVED_REGEX to RESERVED_FEATURE_NAME_PATTERN.

The new name better reflects the meaning. The new type (plain str)
is more appropriate as a constant and can be used in more places.

PiperOrigin-RevId: 515460315

Author: arnoegw

tensorflow_gnn/graph/graph_constants.py

@@ -14,7 +14,6 @@
 # ==============================================================================
 """Constant strings used throughout the package."""
 
-import re
 from typing import Any, List, Mapping, Optional, Sequence, Tuple, Union
 
 import tensorflow as tf
@@ -36,16 +35,15 @@
 SOURCE_NAME = '#source'
 TARGET_NAME = '#target'
 RESERVED_FEATURES = frozenset({SIZE_NAME, SOURCE_NAME, TARGET_NAME})
+# The pattern of feature names (present and future) that are not allowed on a
+# graph tensor and schema, for use with re.fullmatch(pattern, feature_name).
+RESERVED_FEATURE_NAME_PATTERN = r'#.*'
 
 # The conventional feature name for the hidden state (neuron activations) of
 # an edge set, a node set or the context. Not special in GraphTensor, but used
 # in some modeling libraries on top if explicit names are not needed.
 HIDDEN_STATE = 'hidden_state'
 
-# The pattern of feature names that are not allowed on a graph tensor and
-# schema.
-RESERVED_REGEX = re.compile(r'#.*')
-
 # The internal metadata key prefix to use for hyper adjacency.
 INDEX_KEY_PREFIX = '#index.'
 

tensorflow_gnn/graph/schema_validation.py

@@ -14,6 +14,7 @@
 # ==============================================================================
 """Graph schema validation routines."""
 
+import re
 from typing import List, Optional, Sequence
 
 from absl import logging  # TODO(blais): Remove, see below.
@@ -235,7 +236,7 @@ def _validate_schema_reserved_feature_names(schema: schema_pb2.GraphSchema):
   # TODO(blais): Make this compulsory after we remove the hardcoded
   # feature names from the sampler.
   for set_type, set_name, feature_name, feature in su.iter_features(schema):
-    if const.RESERVED_REGEX.match(feature_name):
+    if re.fullmatch(const.RESERVED_FEATURE_NAME_PATTERN, feature_name):
       logging.error("Invalid %s feature name '%s' on set '%s': reserved names "
                     "are not allowed", set_type, feature_name, set_name)