refactor the parsing

dotdrop/linktypes.py

@@ -5,3 +5,15 @@ class LinkTypes(IntEnum):
     NOLINK = 0
     LINK = 1
     LINK_CHILDREN = 2
+
+    @classmethod
+    def get(cls, key, default=None):
+        try:
+            return key if isinstance(key, cls) else cls[key.upper()]
+        except KeyError:
+            if default:
+                return default
+            raise ValueError('bad {} value: "{}"'.format(cls.__name__, key))
+
+    def __str__(self):
+        return self.name.lower()