[commands] Add Command.parents

Make command.root_parent use new command.parents property

discord/ext/commands/core.py

@@ -504,13 +504,17 @@ class Command(_BaseCommand):
         return ' '.join(reversed(entries))
 
     @property
-    def root_parent(self):
-        """Retrieves the root parent of this command.
+    def parents(self):
+        """Retrieves the parents of this command.
+
+        .. versionadded:: 1.1.0
+
+        If the command has no parents then it returns an empty :class:`list`.
+
+        For example in commands ``?a b c test``,
+        the parents are ``[c, b, a]``.
 
-        If the command has no parents then it returns ``None``.
 
-        For example in commands ``?a b c test``, the root parent is
-        ``a``.
         """
         entries = []
         command = self
@@ -518,10 +522,20 @@ class Command(_BaseCommand):
             command = command.parent
             entries.append(command)
 
-        if len(entries) == 0:
-            return None
+        return entries
 
-        return entries[-1]
+    @property
+    def root_parent(self):
+        """Retrieves the root parent of this command.
+
+        If the command has no parents then it returns ``None``.
+
+        For example in commands ``?a b c test``, the root parent is
+        ``a``.
+        """
+        if not self.parent:
+            return None
+        return self.parents[-1]
 
     @property
     def qualified_name(self):