Implement conversion of numerically-index objects to arrays

pyhocon/config_tree.py

@@ -317,6 +317,19 @@ def get_list(self, key, default=UndefinedKey):
         value = self.get(key, default)
         if isinstance(value, list):
             return value
+        elif isinstance(value, ConfigTree):
+            try:
+                lst = []
+                sorted_tree = sorted(value.items())
+                for k, v in sorted_tree:
+                    if re.match('^[1-9][0-9]*$|0', k):
+                        lst.append(v)
+                    else:
+                        raise ValueError
+                return lst
+            except ValueError:
+                raise ConfigException(
+                    u"{key} does not translate to a list".format(key=key))
         elif value is None:
             return None
         else:

tests/test_config_tree.py

@@ -33,6 +33,17 @@ def test_config_list(self):
         config_tree.put("a.b.c", [8, 9], True)
         assert config_tree.get("a.b.c") == [6, 7, 8, 9]
 
+    def test_numerically_index_objects_to_arrays(self):
+        config_tree = ConfigTree()
+        config_tree.put("list.2", "b")
+        config_tree.put("list.0", "a")
+        assert config_tree.get_list("list") == ["a", "b"]
+
+        config_tree.put("invalid-list.a", "c")
+        config_tree.put("invalid-list.b", "d")
+        with pytest.raises(ConfigException):
+            config_tree.get_list("invalid-list")
+
     def test_config_tree_number(self):
         config_tree = ConfigTree()
         config_tree.put("a.b.c", 5)