Add __delitem__ to sorted dict views

Author: grantjenks

docs/sorteddict.rst

@@ -57,6 +57,7 @@ SortedKeysView
    :show-inheritance:
 
    .. automethod:: __getitem__
+   .. automethod:: __delitem__
 
 
 SortedItemsView
@@ -66,6 +67,7 @@ SortedItemsView
    :show-inheritance:
 
    .. automethod:: __getitem__
+   .. automethod:: __delitem__
 
 
 SortedValuesView
@@ -75,3 +77,4 @@ SortedValuesView
    :show-inheritance:
 
    .. automethod:: __getitem__
+   .. automethod:: __delitem__

sortedcontainers/sorteddict.py

@@ -543,6 +543,44 @@ def _check(self):
         assert all(key in self for key in _list)
 
 
+def _view_delitem(self, index):
+    """Remove item at `index` from sorted dict.
+
+    ``view.__delitem__(index)`` <==> ``del view[index]``
+
+    Support slicing.
+
+    Runtime complexity: `O(log(n))` -- approximate.
+
+    >>> sd = SortedDict({'a': 1, 'b': 2, 'c': 3})
+    >>> view = sd.keys()
+    >>> del view[0]
+    >>> sd
+    SortedDict({'b': 2, 'c': 3})
+    >>> del view[-1]
+    >>> sd
+    SortedDict({'b': 2})
+    >>> del view[:]
+    >>> sd
+    SortedDict({})
+
+    :param index: integer or slice for indexing
+    :raises IndexError: if index out of range
+
+    """
+    _mapping = self._mapping
+    _list = _mapping._list
+    _dict_delitem = _mapping._dict_delitem
+    if isinstance(index, slice):
+        keys = _list[index]
+        del _list[index]
+        for key in keys:
+            _dict_delitem(key)
+    else:
+        key = _list.pop(index)
+        _dict_delitem(key)
+
+
 class SortedKeysView(KeysView, Sequence):
     """Sorted keys view is a dynamic view of the sorted dict's keys.
 
@@ -584,6 +622,9 @@ def __getitem__(self, index):
         return self._mapping._list[index]
 
 
+    __delitem__ = _view_delitem
+
+
 class SortedItemsView(ItemsView, Sequence):
     """Sorted items view is a dynamic view of the sorted dict's items.
 
@@ -633,6 +674,9 @@ def __getitem__(self, index):
         return key, _mapping[key]
 
 
+    __delitem__ = _view_delitem
+
+
 class SortedValuesView(ValuesView, Sequence):
     """Sorted values view is a dynamic view of the sorted dict's values.
 
@@ -680,3 +724,6 @@ def __getitem__(self, index):
 
         key = _mapping_list[index]
         return _mapping[key]
+
+
+    __delitem__ = _view_delitem