Implement "Fraction.is_integer()", following python/cpython#100488

Author: scoder

src/quicktions.pyx

@@ -509,6 +509,10 @@ cdef class Fraction:
         else:
             return cls(digits, pow10(-exp))
 
+    def is_integer(self):
+        """Return True if the Fraction is an integer."""
+        return self._denominator == 1
+
     def as_integer_ratio(self):
         """Return the integer ratio as a tuple.
 

src/test_fractions.py

@@ -468,6 +468,19 @@ def testFromDecimal(self):
             ValueError, "Cannot convert sNaN to Fraction.",
             F.from_decimal, Decimal("snan"))
 
+    def test_is_integer(self):
+        self.assertTrue(F(1, 1).is_integer())
+        self.assertTrue(F(-1, 1).is_integer())
+        self.assertTrue(F(1, -1).is_integer())
+        self.assertTrue(F(2, 2).is_integer())
+        self.assertTrue(F(-2, 2).is_integer())
+        self.assertTrue(F(2, -2).is_integer())
+
+        self.assertFalse(F(1, 2).is_integer())
+        self.assertFalse(F(-1, 2).is_integer())
+        self.assertFalse(F(1, -2).is_integer())
+        self.assertFalse(F(-1, -2).is_integer())
+
     def test_as_integer_ratio(self):
         self.assertEqual(F(4, 6).as_integer_ratio(), (2, 3))
         self.assertEqual(F(-4, 6).as_integer_ratio(), (-2, 3))