Now that we require Py3.8, use the walrus operator in a few places.

PiperOrigin-RevId: 487858073

Author: lingvo-bot

lingvo/core/base_layer.py

@@ -545,8 +545,7 @@ def GetDescendant(self, path: str) -> BaseLayerT:
       # If child_name is being indexed as a list then we separate the name and
       # the index.
       index = None
-      match = re.match(r'(.*)\[([-]?[0-9]+)\]$', child_name)
-      if match:
+      if match := re.match(r'(.*)\[([-]?[0-9]+)\]$', child_name):
         child_name, index = match.group(1), int(match.group(2))
 
       # Validate that child_name is a child of the current parent layer.

lingvo/core/hyperparams.py

@@ -72,8 +72,7 @@ def _UnquoteString(quoted):
 
 def _EndsWithTerminalQuote(s, quote_char):
   """Returns whether a string ends with a valid terminal quote."""
-  endm = re.search(r'(\\*)%s$' % quote_char, s)
-  if not endm:
+  if not (endm := re.search(r'(\\*)%s$' % quote_char, s)):
     return False
   backslashes = endm.group(1)
   if len(backslashes) % 2 == 0:
@@ -362,8 +361,7 @@ def _GetNested(self, name: str) -> Tuple[ParamsT, str]:
     for i, part in enumerate(parts[:-1]):
       # Get the value (nested Params object) associated with name 'part'.
       try:
-        is_list = re.match(r'^(.+)\[(.+)\]$', part)
-        if is_list:
+        if is_list := re.match(r'^(.+)\[(.+)\]$', part):
           part = is_list.group(1)
           list_index = int(is_list.group(2))
         # pylint: disable=protected-access

lingvo/core/py_utils.py

@@ -1471,8 +1471,7 @@ def GetVariableName(name):
         ('Renaming variables is not supported in eager mode. '
          'Please look into migrating away from variable renaming.'), 1)
     for regexp, name_format in renames:
-      match = re.match(regexp, name)
-      if match:
+      if match := re.match(regexp, name):
         if matched:
           tf.logging.warning('Multiple matches for: %s', name)
         matched = True
@@ -2702,9 +2701,8 @@ def _GetVarsToLoad(all_vars,
   for model_var in all_vars:
     loaded = False
     for regexp, name_format in variable_loading_rules:
-      match = re.match(regexp, model_var.name)
       # Skip if var doesn't match the loading rules, or if it should be ignored.
-      if not match:
+      if not (match := re.match(regexp, model_var.name)):
         if not suppress_logging:
           tf.logging.debug('Loading rules do not match %s.', model_var.name)
         continue
@@ -5142,9 +5140,7 @@ def RecordFormatFromFilePattern(file_pattern):
       - record_format: String record format, e.g., "tfrecord", etc.
       - file_pattern: The file pattern without any prefixes.
   """
-  result = re.match(_RECORD_FORMAT_RE, file_pattern)
-
-  if result is None:
+  if (result := re.match(_RECORD_FORMAT_RE, file_pattern)) is None:
     # TODO(vrv): Fix all callers so that file_pattern must contain
     # the record format prefix.
     return 'sstable', file_pattern

lingvo/models_test_helper.py

@@ -181,10 +181,10 @@ def CreateTestMethodsForAllRegisteredModels(cls,
     print(f'Creating tests for {task_regexes}, excluding {exclude_regexes}')
     valid_models = []
     for model_name in sorted(model_names):
-      if not any([re.search(regex, model_name) for regex in task_regexes]):
+      if not any(re.search(regex, model_name) for regex in task_regexes):
         print(f'Skipping tests for registered model {model_name}')
         continue
-      if any([re.search(regex, model_name) for regex in exclude_regexes]):
+      if any(re.search(regex, model_name) for regex in exclude_regexes):
         print(f'Explicitly excluding tests for registered model {model_name}')
         continue
       valid_models.append(model_name)