py3: keys() is an iterator so need a list if modifying
py3: keys() is an iterator so need a list if modifying

mkeilman/sirepo,mkeilman/sirepo,radiasoft/sirepo,radiasoft/sirepo,radiasoft/sirepo,mkeilman/sirepo,mkeilman/sirepo,radiasoft/sirepo,radiasoft/sirepo