huge cleanup for removing mutables used as default

[sfa.git] / sfa / rspecs / elements / versions / nitosv1PLTag.py

diff --git a/sfa/rspecs/elements/versions/nitosv1PLTag.py b/sfa/rspecs/elements/versions/nitosv1PLTag.py
index 7d03fe0..ea34ff4 100644 (file)
--- a/sfa/rspecs/elements/versions/nitosv1PLTag.py
+++ b/sfa/rspecs/elements/versions/nitosv1PLTag.py
@@ -9,7 +9,8 @@ class NITOSv1PLTag:
             pl_tag_elem.set_text(value)
               
     @staticmethod
-    def get_pl_tags(xml, ignore=[]):
+    def get_pl_tags(xml, ignore=None):
+        if ignore is None: ignore=[]
         pl_tags = []
         for elem in xml.iterchildren():
             if elem.tag not in ignore: