Added delete option to database storage.

venv/Lib/site-packages/cachetools/rr.py

@@ -0,0 +1,35 @@
+import random
+
+from .cache import Cache
+
+
+# random.choice cannot be pickled in Python 2.7
+def _choice(seq):
+    return random.choice(seq)
+
+
+class RRCache(Cache):
+    """Random Replacement (RR) cache implementation."""
+
+    def __init__(self, maxsize, choice=random.choice, getsizeof=None):
+        Cache.__init__(self, maxsize, getsizeof)
+        # TODO: use None as default, assing to self.choice directly?
+        if choice is random.choice:
+            self.__choice = _choice
+        else:
+            self.__choice = choice
+
+    @property
+    def choice(self):
+        """The `choice` function used by the cache."""
+        return self.__choice
+
+    def popitem(self):
+        """Remove and return a random `(key, value)` pair."""
+        try:
+            key = self.__choice(list(self))
+        except IndexError:
+            msg = '%s is empty' % self.__class__.__name__
+            raise KeyError(msg) from None
+        else:
+            return (key, self.pop(key))