safe deletion for ordered maps

attmap/attmap.py

@@ -6,7 +6,7 @@
 else:
     from collections.abc import Mapping
 
-from .helpers import copy, get_logger
+from .helpers import copy, get_logger, safedel_message
 from ._att_map_like import AttMapLike
 
 
@@ -26,7 +26,7 @@ def __delitem__(self, key):
         try:
             del self.__dict__[key]
         except KeyError:
-            _LOGGER.debug("No key {} to delete".format(key))
+            _LOGGER.debug(safedel_message(key))
 
     def __getitem__(self, item):
         return self.__dict__[item]

attmap/helpers.py

@@ -91,3 +91,13 @@ def is_custom_map(obj):
     :return bool: whether the object is a Mapping other than dict
     """
     return isinstance(obj, Mapping) and type(obj) is not dict
+
+
+def safedel_message(key):
+    """
+    Create safe deletion log message.
+
+    :param hashable key: unmapped key for which deletion/removal was tried
+    :return str: message to log unmapped key deletion attempt.
+    """
+    return "No key {} to delete".format(key)

attmap/ordattmap.py

@@ -2,13 +2,17 @@
 
 from collections import OrderedDict
 from .attmap import AttMap
+from .helpers import get_logger, safedel_message
 
 __author__ = "Vince Reuter"
 __email__ = "vreuter@virginia.edu"
 
 __all__ = ["OrdAttMap"]
 
 
+_LOGGER = get_logger(__name__)
+
+
 class OrdAttMap(OrderedDict, AttMap):
     """ Insertion-ordered mapping with dot notation access """
 
@@ -18,6 +22,13 @@ def __init__(self, entries=None):
     def __setitem__(self, key, value):
         super(OrdAttMap, self).__setitem__(key, self._finalize_value(value))
 
+    def __delitem__(self, key):
+        """ Make unmapped key deletion unexceptional. """
+        try:
+            super(OrdAttMap, self).__delitem__(key)
+        except KeyError:
+            _LOGGER.debug(safedel_message(key))
+
     def __eq__(self, other):
         return AttMap.__eq__(self, other) and list(self.keys()) == list(other.keys())
 

tests/test_basic_ops_dynamic.py

@@ -68,6 +68,18 @@ def test_add_pandas_series(series, attmap_type):
     assert raw_data == {k: m[k] for k in raw_data}
 
 
+@pytest.mark.parametrize("seed_data", [{}, {"a": 1}, {"b": 2, "c": 3}])
+@pytest.mark.parametrize("delkey", ["d", "e"])
+def test_del_unmapped_key(attmap_type, seed_data, delkey):
+    """ Attempt to remove unmapped key should not fail. """
+    m = get_att_map(attmap_type, entries=seed_data)
+    assert delkey not in m
+    try:
+        del m[delkey]
+    except KeyError as e:
+        pytest.fail("Attempt to remove unmapped key hit exception: {}".format(e))
+
+
 @pytest.mark.parametrize("f_extra_checks_pair",
     [(repr, []), (str, [lambda s, dt: s.startswith(dt.__name__)])])
 def test_text(attmap_type, entries, f_extra_checks_pair):