pull out and test table; refs #29 and #15

mergic/mergic.py

@@ -226,17 +226,37 @@ def apply_diff_(args):
     print_json(partition)
 
 
+def table(partition):
+    """Generate 'merge table' rows from a partition.
+
+    Parameters
+    ----------
+    partition : dict
+        A partition dictionary where the values are lists. Items appear
+        exactly once through all the value lists (they are "assigned to"
+        their key value.)
+
+    Yields
+    ------
+    tuple
+        Pairs of original and new names, as specified in the partition,
+        encoded in UTF-8.
+
+    """
+    for key, values in partition.items():
+        for value in values:
+            yield (value, key)
+
+
 def table_(args):
     """Print out a two-column 'merge table' at the command line."""
-    data = json.loads(args.partition.read())
-    check(data)
+    partition = json.loads(args.partition.read())
+    check(partition)
     writer = csv.writer(sys.stdout)
     writer.writerow(["original", "mergic"])
-    for key, values in data.items():
-        key = key.encode('utf-8')
-        for value in values:
-            value = value.encode('utf-8')
-            writer.writerow([value, key])
+    for row in table(partition):
+        row = [str(element).encode('utf-8') for element in row]
+        writer.writerow(row)
 
 
 def _calc_(self, args):

mergic/test.py

@@ -91,5 +91,20 @@ def test_slightly_interesting_equality(self):
                                      {2: ['a'], 1: [3, 2, 1]}))
 
 
+class TestTable(unittest.TestCase):
+
+    def test_nothing_for_empty(self):
+        self.assertEqual(len(list(mergic.table({}))), 0)
+
+    def test_right_number_of_rows(self):
+        p = {1: [2, 3], 'b': [4, 5, 6]}
+        self.assertEqual(len(list(mergic.table(p))), 5)
+
+    def test_correct_rows_appear(self):
+        p = {1: [2, 3], 'b': [4, 5, 6]}
+        rowset = set([(2, 1), (3, 1), (4, 'b'), (5, 'b'), (6, 'b')])
+        self.assertEqual(set(mergic.table(p)), rowset)
+
+
 if __name__ == '__main__':
     unittest.main()