support empty choice

tiramisu_cmdline_parser/api.py

@@ -26,7 +26,7 @@ except ImportError:
     RequirementError = PropertiesOptionError
     LeadershipError = ValueError
 try:
-    from tiramisu__api import Config as ConfigJson
+    from tiramisu_api import Config as ConfigJson
     if Config is None:
         Config = ConfigJson
 except ImportError:
@@ -39,7 +39,7 @@ def get_choice_list(obj, properties, display):
             return str(choice)
         return choice
     choices = [convert(choice) for choice in obj.value.list()]
-    if choices[0] == '':
+    if choices and choices[0] == '':
         del choices[0]
     if display:
         choices = '{{{}}}'.format(','.join(choices))