Revert "Merge branch 'python3-cmp' into 'master'"

This reverts merge request !4

ligo/segments.py

@@ -137,23 +137,18 @@ class infinity(object):
 
 	# tests
 
-	def __lt__(self, other):
-		return self is NegInfinity and other is not NegInfinity
-
-	def __gt__(self, other):
-		return self is PosInfinity and other is not PosInfinity
-
-	def __le__(self, other):
-		return self is NegInfinity or other is PosInfinity
-
-	def __ge__(self, other):
-		return self is PosInfinity or other is NegInfinity
-
-	def __eq__(self, other):
-		return self is other
-
-	def __ne__(self, other):
-		return self is not other
+	def __cmp__(self, other):
+		"""
+		Positive infinity compares as greater than everything
+		except itself, negative infinity compares as less than
+		everything except itself.
+		"""
+		if self is other:
+			return 0
+		if self is PosInfinity:
+			return 1
+		# self is NegInfinity
+		return -1
 
 	def __nonzero__(self):
 		"""

test/segments_verify.py

@@ -67,17 +67,6 @@ def set2():
 
 
 class test_infinity(unittest.TestCase):
-	def test_math(self):
-		a = segments.infinity()
-		self.assertEqual(-a, -a)
-		self.assertLess(-a, 0)
-		self.assertLess(-a, a)
-		self.assertGreater(0, -a)
-		self.assertLess(0, a)
-		self.assertGreater(a, -a)
-		self.assertGreater(a, 0)
-		self.assertEqual(a, a)
-
 	@unittest.skipIf(sys.version_info.major >= 3,
 		'Python 3 does not have cmp')
 	def test__cmp__(self):