Allow pendulum comparison to None. (#30)

Author: jkeyes

pendulum/pendulum.py

@@ -2139,6 +2139,9 @@ def _get_datetime(self, value, pendulum=False):
 
         :rtype: datetime or Pendulum
         """
+        if value is None:
+            return None
+
         if isinstance(value, Pendulum):
             return value._datetime if not pendulum else value
 

tests/pendulum_tests/test_comparison.py

@@ -65,6 +65,11 @@ def test_not_equal_with_timezone_true(self):
         self.assertNotEqual(d1, d2)
         self.assertEqual(d1, d3)
 
+    def test_not_equal_to_none(self):
+        d1 = Pendulum(2000, 1, 1, 1, 2, 3)
+
+        self.assertNotEqual(d1, None)
+
     def test_greater_than_true(self):
         d1 = Pendulum(2000, 1, 1)
         d2 = Pendulum(1999, 12, 31)