cast to object type when replacing nans with None's df.where() doesn't seem to be doing this implicitly in some cases
cast to object type when replacing nans with None's
df.where() doesn't seem to be doing this implicitly in some cases

ocefpaf/ulmo,cameronbracken/ulmo,ocefpaf/ulmo,nathanhilbert/ulmo,nathanhilbert/ulmo,cameronbracken/ulmo