Resolve "`sample_subset` in `PriorSet` should not have have `list()` as a default argument for `keys`"

Closes #154 (closed)

tupak/core/prior.py

@@ -147,7 +147,7 @@ class PriorSet(dict):
         """
         return self.sample_subset(keys=self.keys(), size=size)
 
-    def sample_subset(self, keys=list(), size=None):
+    def sample_subset(self, keys=iter([]), size=None):
         """Draw samples from the prior set for parameters which are not a DeltaFunction
 
         Parameters
@@ -377,7 +377,7 @@ class Prior(object):
         """
         return self._subclass_repr_helper()
 
-    def _subclass_repr_helper(self, subclass_args=None):
+    def _subclass_repr_helper(self, subclass_args=iter([])):
         """Helps out subclass _repr__ methods by creating a common template
 
         Parameters
@@ -392,8 +392,7 @@ class Prior(object):
         """
         prior_name = self.__class__.__name__
         args = ['name', 'latex_label', 'minimum', 'maximum']
-        if subclass_args is not None:
-            args.extend(subclass_args)
+        args.extend(subclass_args)
 
         property_names = [p for p in dir(self.__class__) if isinstance(getattr(self.__class__, p), property)]
         dict_with_properties = self.__dict__.copy()