base: mkarg: Fix typing.Unions to select first type

Signed-off-by: John Andersen <[email protected]>
johnandersen777 · May 23, 2022 · 98f0234 · 98f0234
1 parent 14d44b4
commit 98f0234
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/dffml/base.py b/dffml/base.py
@@ -126,9 +126,10 @@ def mkarg(field):
         if hasattr(arg["type"], "load"):
             # TODO (python3.8) Use Protocol
             arg["type"] = arg["type"].load
-    elif get_origin(field.type) in (list, tuple):
+    elif get_origin(field.type) in (list, tuple, Union):
         arg["type"] = get_args(field.type)[0]
-        arg["nargs"] = "+"
+        if get_origin(field.type) in (list, tuple):
+            arg["nargs"] = "+"
     if "description" in field.metadata:
         arg["help"] = field.metadata["description"]
     if field.metadata.get("action"):