ParamsDict update.

PiperOrigin-RevId: 307639416

official/modeling/hyperparams/params_dict.py

@@ -125,6 +125,25 @@ class ParamsDict(object):
     """Accesses through built-in dictionary get method."""
     return self.__dict__.get(key, value)
 
+  def __delattr__(self, k):
+    """Deletes the key and removes its values.
+
+    Args:
+      k: the key string.
+
+    Raises:
+      AttributeError: if k is reserverd or not defined in the ParamsDict.
+      ValueError: if the ParamsDict instance has been locked.
+    """
+    if k in ParamsDict.RESERVED_ATTR:
+      raise AttributeError('The key `{}` is reserved. No change is allowes. '
+                           .format(k))
+    if k not in self.__dict__.keys():
+      raise AttributeError('The key `{}` does not exist. '.format(k))
+    if self._locked:
+      raise ValueError('The ParamsDict has been locked. No change is allowed.')
+    del self.__dict__[k]
+
   def override(self, override_params, is_strict=True):
     """Override the ParamsDict with a set of given params.
 
@@ -286,7 +305,6 @@ def read_yaml_to_params_dict(file_path):
 def save_params_dict_to_yaml(params, file_path):
   """Saves the input ParamsDict to a YAML file."""
   with tf.io.gfile.GFile(file_path, 'w') as f:
-
     def _my_list_rep(dumper, data):
       # u'tag:yaml.org,2002:seq' is the YAML internal tag for sequence.
       return dumper.represent_sequence(

official/modeling/hyperparams/params_dict_test.py

@@ -13,7 +13,7 @@
 # limitations under the License.
 # ==============================================================================
 
-"""Tests for official.modeling.hyperparams.params_dict.py."""
+"""Tests for params_dict.py."""
 
 import os
 
@@ -45,12 +45,14 @@ class ParamsDictTest(tf.test.TestCase):
     self.assertEqual(params.b, 2)
 
   def test_lock(self):
-    params = params_dict.ParamsDict({'a': 1, 'b': 2})
+    params = params_dict.ParamsDict({'a': 1, 'b': 2, 'c': 3})
     params.lock()
     with self.assertRaises(ValueError):
       params.a = 10
     with self.assertRaises(ValueError):
       params.override({'b': 20})
+    with self.assertRaises(ValueError):
+      del params.c
 
   def test_setattr(self):
     params = params_dict.ParamsDict()
@@ -69,6 +71,20 @@ class ParamsDictTest(tf.test.TestCase):
     self.assertEqual(params.b, 2)
     self.assertEqual(params.c, None)
 
+  def test_delattr(self):
+    params = params_dict.ParamsDict()
+    params.override(
+        {'a': 'aa', 'b': 2, 'c': None, 'd': {'d1': 1, 'd2': 10}},
+        is_strict=False)
+    del params.c
+    self.assertEqual(params.a, 'aa')
+    self.assertEqual(params.b, 2)
+    with self.assertRaises(AttributeError):
+      _ = params.c
+    del params.d
+    with self.assertRaises(AttributeError):
+      _ = params.d.d1
+
   def test_contains(self):
     params = params_dict.ParamsDict()
     params.override(