Issue 488/remove mutable default args in io model (#692)

panel/io/model.py

@@ -12,7 +12,6 @@
 
 from .state import state
 
-
 #---------------------------------------------------------------------
 # Public API
 #---------------------------------------------------------------------
@@ -62,11 +61,16 @@ def add_to_doc(obj, doc, hold=False):
         doc.hold()
 
 
-def bokeh_repr(obj, depth=0, ignored=['children', 'text', 'name', 'toolbar', 'renderers', 'below', 'center', 'left', 'right']):
+_DEFAULT_IGNORED_REPR = frozenset(['children', 'text', 'name', 'toolbar', 'renderers', 'below', 'center', 'left', 'right'])
+
+def bokeh_repr(obj, depth=0, ignored=None):
     """
     Returns a string repr for a bokeh model, useful for recreating
     panel objects using pure bokeh.
     """
+    if ignored is None:
+        ignored = _DEFAULT_IGNORED_REPR
+
     from ..viewable import Viewable
     if isinstance(obj, Viewable):
         obj = obj.get_root(Document())

panel/io/save.py

@@ -46,7 +46,7 @@ def save_png(model, filename):
 #---------------------------------------------------------------------
 
 def save(panel, filename, title=None, resources=None, template=None,
-         template_variables={}, embed=False, max_states=1000,
+         template_variables=None, embed=False, max_states=1000,
          max_opts=3, embed_json=False, json_prefix='', save_path='./',
          load_path=None):
     """
@@ -62,6 +62,10 @@ def save(panel, filename, title=None, resources=None, template=None,
       Optional title for the plot
     resources: bokeh resources
       One of the valid bokeh.resources (e.g. CDN or INLINE)
+    template:
+      template file, as used by bokeh.file_html. If None will use bokeh defaults
+    template_variables:
+      template_variables file dict, as used by bokeh.file_html
     embed: bool
       Whether the state space should be embedded in the saved file.
     max_states: int
@@ -101,6 +105,8 @@ def save(panel, filename, title=None, resources=None, template=None,
         resources = CDN
     if template:
         kwargs['template'] = template
+    if template_variables:
+        kwargs['template_variables'] = template_variables
 
     html = file_html(doc, resources, title, **kwargs)
     if hasattr(filename, 'write'):