PYTHON-2466 Make pymongo client, database and collection objects hashable. (#533)

(cherry picked from commit 733ab25)

Author: pcorpet

pymongo/collection.py

@@ -303,6 +303,9 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self == other
 
+    def __hash__(self):
+        return hash((self.__database, self.__name))
+
     @property
     def full_name(self):
         """The full name of this :class:`Collection`.

pymongo/database.py

@@ -272,6 +272,9 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self == other
 
+    def __hash__(self):
+        return hash((self.__client, self.__name))
+
     def __repr__(self):
         return "Database(%r, %r)" % (self.__client, self.__name)
 

pymongo/mongo_client.py

@@ -1509,6 +1509,9 @@ def __eq__(self, other):
     def __ne__(self, other):
         return not self == other
 
+    def __hash__(self):
+        return hash(self.address)
+
     def _repr_helper(self):
         def option_repr(option, value):
             """Fix options whose __repr__ isn't usable in a constructor."""

test/test_client.py

@@ -627,6 +627,10 @@ def test_equality(self):
         # Explicitly test inequality
         self.assertFalse(client_context.client != c)
 
+    def test_hashable(self):
+        c = connected(rs_or_single_client())
+        self.assertIn(c, {client_context.client})
+
     def test_host_w_port(self):
         with self.assertRaises(ValueError):
             connected(MongoClient("%s:1234567" % (client_context.host,),

test/test_collection.py

@@ -154,6 +154,9 @@ def test_equality(self):
         self.assertEqual(self.db.test.mike, self.db["test.mike"])
         self.assertEqual(self.db.test["mike"], self.db["test.mike"])
 
+    def test_hashable(self):
+        self.assertIn(self.db.test.mike, {self.db["test.mike"]})
+
     @client_context.require_version_min(3, 3, 9)
     def test_create(self):
         # No Exception.

test/test_database.py

@@ -126,6 +126,9 @@ def test_equality(self):
         self.assertFalse(Database(self.client, "test") !=
                          Database(self.client, "test"))
 
+    def test_hashable(self):
+        self.assertIn(self.client.test, {Database(self.client, "test")})
+
     def test_get_coll(self):
         db = Database(self.client, "pymongo_test")
         self.assertEqual(db.test, db["test"])