The exception comes up in the printing part of the output, not the actual reducing. Last part of the stacktrace is:
/Users/mcraig/anaconda/envs/ast366/lib/python3.5/site-packages/reducer/astro_gui.py in __str__(self)
849
850 def __str__(self):
--> 851 for k, v in six.iteritems(self.values):
852 if v == self.value:
853 return k
AttributeError: 'PolynomialDropdown' object has no attribute 'values'
The exception comes up in the printing part of the output, not the actual reducing. Last part of the stacktrace is: