clean up comments and tests

src/monty/collections.py

@@ -20,7 +20,7 @@ def tree() -> collections.defaultdict:
 
     Usage:
         x = tree()
-        x['a']['b']['c'] = 1
+        x["a"]["b"]["c"] = 1
 
     Returns:
         A tree.
@@ -31,7 +31,7 @@ def tree() -> collections.defaultdict:
 class frozendict(dict):
     """
     A dictionary that does not permit changes. The naming
-    violates PEP8 to be consistent with standard Python's "frozenset" naming.
+    violates PEP 8 to be consistent with standard Python's "frozenset" naming.
     """
 
     def __init__(self, *args, **kwargs) -> None:
@@ -55,7 +55,7 @@ def update(self, *args, **kwargs) -> None:
 
 
 class Namespace(dict):
-    """A dictionary that does not permit to redefine its keys."""
+    """A dictionary that does not permit changing its values."""
 
     def __init__(self, *args, **kwargs) -> None:
         """
@@ -67,7 +67,7 @@ def __init__(self, *args, **kwargs) -> None:
 
     def __setitem__(self, key: Any, val: Any) -> None:
         if key in self:
-            raise KeyError(f"Cannot overwrite existent key: {key!s}")
+            raise KeyError(f"Cannot overwrite existing key: {key!s}")
 
         dict.__setitem__(self, key, val)
 
@@ -83,14 +83,14 @@ def update(self, *args, **kwargs) -> None:
 
 class AttrDict(dict):
     """
-    Allows to access dict keys as obj.foo in addition
-    to the traditional way obj['foo']"
+    Allows to access values as dct.key in addition
+    to the traditional way dct["key"]
 
     Examples:
-        >>> d = AttrDict(foo=1, bar=2)
-        >>> assert d["foo"] == d.foo
-        >>> d.bar = "hello"
-        >>> assert d.bar == "hello"
+        >>> dct = AttrDict(foo=1, bar=2)
+        >>> assert dct["foo"] == dct.foo
+        >>> dct.bar = "hello"
+        >>> assert dct.bar == "hello"
     """
 
     def __init__(self, *args, **kwargs) -> None:
@@ -114,9 +114,9 @@ def copy(self) -> Self:
 class FrozenAttrDict(frozendict):
     """
     A dictionary that:
-        * does not permit changes.
-        * Allows to access dict keys as obj.foo in addition
-          to the traditional way obj['foo']
+        - Does not permit changes.
+        - Allows to access values as dct.key in addition
+          to the traditional way dct["key"]
     """
 
     def __init__(self, *args, **kwargs) -> None:
@@ -186,7 +186,6 @@ def __getattribute__(self, name: str) -> Any:
         try:
             return super().__getattribute__(name)
         except AttributeError:
-            # raise
             try:
                 a = self._mongo_dict_[name]
                 if isinstance(a, collections.abc.Mapping):
@@ -232,8 +231,8 @@ def dict2namedtuple(*args, **kwargs) -> tuple:
         - Don't use this function in code in which memory and performance are
           crucial since a dict is needed to instantiate the tuple!
     """
-    d = collections.OrderedDict(*args)
-    d.update(**kwargs)
+    dct = collections.OrderedDict(*args)
+    dct.update(**kwargs)
     return collections.namedtuple(
-        typename="dict2namedtuple", field_names=list(d.keys())
-    )(**d)
+        typename="dict2namedtuple", field_names=list(dct.keys())
+    )(**dct)

tests/test_collections.py

@@ -9,47 +9,56 @@
 TEST_DIR = os.path.join(os.path.dirname(__file__), "test_files")
 
 
-class TestFrozenDict:
-    def test_frozen_dict(self):
-        d = frozendict({"hello": "world"})
-        with pytest.raises(KeyError):
-            d["k"] == "v"
-        assert d["hello"] == "world"
-
-    def test_namespace_dict(self):
-        d = Namespace(foo="bar")
-        d["hello"] = "world"
-        assert d["foo"] == "bar"
-        with pytest.raises(KeyError):
-            d.update({"foo": "spam"})
-
-    def test_attr_dict(self):
-        d = AttrDict(foo=1, bar=2)
-        assert d.bar == 2
-        assert d["foo"] == d.foo
-        d.bar = "hello"
-        assert d["bar"] == "hello"
-
-    def test_frozen_attrdict(self):
-        d = FrozenAttrDict({"hello": "world", 1: 2})
-        assert d["hello"] == "world"
-        assert d.hello == "world"
-        with pytest.raises(KeyError):
-            d["updating"] == 2
-
-        with pytest.raises(KeyError):
-            d["foo"] = "bar"
-        with pytest.raises(KeyError):
-            d.foo = "bar"
-        with pytest.raises(KeyError):
-            d.hello = "new"
-
-
-class TestTree:
-    def test_tree(self):
-        x = tree()
-        x["a"]["b"]["c"]["d"] = 1
-        assert "b" in x["a"]
-        assert "c" not in x["a"]
-        assert "c" in x["a"]["b"]
-        assert x["a"]["b"]["c"]["d"] == 1
+def test_tree():
+    x = tree()
+    x["a"]["b"]["c"]["d"] = 1
+    assert "b" in x["a"]
+    assert "c" not in x["a"]
+    assert "c" in x["a"]["b"]
+    assert x["a"]["b"]["c"]["d"] == 1
+
+
+def test_frozendict():
+    dct = frozendict({"hello": "world"})
+    assert dct["hello"] == "world"
+
+    with pytest.raises(KeyError, match="Cannot overwrite existing key"):
+        dct["key"] == "val"
+
+    with pytest.raises(KeyError, match="Cannot overwrite existing key"):
+        dct.update(key="value")
+
+
+def test_namespace_dict():
+    dct = Namespace(foo="bar")
+    dct["hello"] = "world"
+    assert dct["key"] == "val"
+
+    with pytest.raises(KeyError, match="Cannot overwrite existing key"):
+        dct["key"] = "val"
+    with pytest.raises(KeyError, match="Cannot overwrite existing key"):
+        dct.update({"key": "val"})
+
+
+def test_attr_dict():
+    dct = AttrDict(foo=1, bar=2)
+    assert dct.bar == 2
+    assert dct["foo"] is dct.foo
+    dct.bar = "hello"
+    assert dct["bar"] == "hello"
+
+
+def test_frozen_attrdict():
+    dct = FrozenAttrDict({"hello": "world", 1: 2})
+    assert dct["hello"] == "world"
+    assert dct.hello == "world"
+
+    # Test adding item
+    with pytest.raises(KeyError, match="You cannot modify attribute"):
+        dct["foo"] = "bar"
+    with pytest.raises(KeyError, match="You cannot modify attribute"):
+        dct.foo = "bar"
+
+    # Test modifying existing item
+    with pytest.raises(KeyError, match="You cannot modify attribute"):
+        dct.hello = "new"