parse_ranges: support for single digits, Bonus2.

parse_ranges/parse_ranges.py

@@ -16,4 +16,16 @@ def parse_ranges_v2(range_string):
             yield number
 
 
-parse_ranges = parse_ranges_v2
+def parse_ranges_v3(range_string):
+    """This version handles single digits, Bonus2."""
+    ranges = [tuple(map(int, r.split("-"))) for r in range_string.split(",")]
+    for limits in ranges:
+        if len(limits) == 1:
+            yield limits[0]
+        else:
+            start, stop = limits
+            for number in range(start, stop + 1):
+                yield number
+
+
+parse_ranges = parse_ranges_v3

parse_ranges/test_parse_ranges.py

@@ -24,7 +24,6 @@ class ParseRangesTests(unittest.TestCase):
         numbers = parse_ranges("100-1000000000000")
         self.assertEqual(next(numbers), 100)
 
-    @unittest.expectedFailure
     def test_with_individual_numbers(self):
         self.assertEqual(
             list(parse_ranges("0,4-8,20,43-45")), [0, 4, 5, 6, 7, 8, 20, 43, 44, 45]