unittest: Add assertAlmostEqual and assertNotAlmostEqual

unittest/test_unittest.py

@@ -14,6 +14,47 @@ class TestUnittestAssertions(unittest.TestCase):
         with self.assertRaises(AssertionError):
             self.assertEqual([0,1,2], [1,2,3])
 
+    def test_AlmostEqual(self):
+        self.assertAlmostEqual(    1.00000001, 1.0)
+        self.assertNotAlmostEqual( 1.0000001, 1.0)
+        with self.assertRaises(AssertionError):
+            self.assertAlmostEqual(1.0000001, 1.0)
+        with self.assertRaises(AssertionError):
+            self.assertNotAlmostEqual(1.00000001, 1.0)
+
+        self.assertAlmostEqual(1.1, 1.0, places=0)
+        with self.assertRaises(AssertionError):
+            self.assertAlmostEqual(1.1, 1.0, places=1)
+
+        self.assertAlmostEqual(0, .1+.1j, places=0)
+        self.assertNotAlmostEqual(0, .1+.1j, places=1)
+        with self.assertRaises(AssertionError):
+            self.assertAlmostEqual(0, .1+.1j, places=1)
+        with self.assertRaises(AssertionError):
+            self.assertNotAlmostEqual(0, .1+.1j, places=0)
+
+        self.assertAlmostEqual(float('inf'), float('inf'))
+        with self.assertRaises(AssertionError):
+            self.assertNotAlmostEqual(float('inf'), float('inf'))
+
+    def test_AmostEqualWithDelta(self):
+        self.assertAlmostEqual(1.1, 1.0, delta=0.5)
+        self.assertAlmostEqual(1.0, 1.1, delta=0.5)
+        self.assertNotAlmostEqual(1.1, 1.0, delta=0.05)
+        self.assertNotAlmostEqual(1.0, 1.1, delta=0.05)
+
+        self.assertAlmostEqual(1.0, 1.0, delta=0.5)
+        with self.assertRaises(AssertionError):
+            self.assertNotAlmostEqual(1.0, 1.0, delta=0.5)
+        with self.assertRaises(AssertionError):
+            self.assertAlmostEqual(1.1, 1.0, delta=0.05)
+        with self.assertRaises(AssertionError):
+            self.assertNotAlmostEqual(1.1, 1.0, delta=0.5)
+        with self.assertRaises(TypeError):
+            self.assertAlmostEqual(1.1, 1.0, places=2, delta=2)
+        with self.assertRaises(TypeError):
+            self.assertNotAlmostEqual(1.1, 1.0, places=2, delta=2)
+
     def testNotEqual(self):
         self.assertNotEqual([0,1,2], [0,2,1])
         with self.assertRaises(AssertionError):

unittest/unittest.py

@@ -33,6 +33,46 @@ class TestCase:
             msg = "%r not expected to be equal %r" % (x, y)
         assert x != y, msg
 
+    def assertAlmostEqual(self, x, y, places=None, msg='', delta=None):
+        if x == y:
+            return
+        if delta is not None and places is not None:
+            raise TypeError("specify delta or places not both")
+
+        if delta is not None:
+            if abs(x - y) <= delta:
+                return
+            if not msg:
+                msg = '%r != %r within %r delta' % (x, y, delta)
+        else:
+            if places is None:
+                places = 7
+            if round(abs(y-x), places) == 0:
+                return
+            if not msg:
+                msg = '%r != %r within %r places' % (x, y, places)
+
+        assert False, msg
+
+    def assertNotAlmostEqual(self, x, y, places=None, msg='', delta=None):
+        if delta is not None and places is not None:
+            raise TypeError("specify delta or places not both")
+
+        if delta is not None:
+            if not (x == y) and abs(x - y) > delta:
+                return
+            if not msg:
+                msg = '%r == %r within %r delta' % (x, y, delta)
+        else:
+            if places is None:
+                places = 7
+            if not (x == y) and round(abs(y-x), places) != 0:
+                return
+            if not msg:
+                msg = '%r == %r within %r places' % (x, y, places)
+
+        assert False, msg
+
     def assertIs(self, x, y, msg=''):
         if not msg:
             msg = "%r is not %r" % (x, y)
@@ -74,6 +114,7 @@ class TestCase:
             raise
 
 
+
 def skip(msg):
     def _decor(fun):
         # We just replace original fun with _inner