compatiable fix for py2.
compatiable fix for py2.

FileNotFoundError is py3 only.

duydb2/thriftpy,maralla/thriftpy,dan-blanchard/thriftpy,duydb2/thriftpy,importcjj/thriftpy,OctavianLee/thriftpy,itnihao/thriftpy,importcjj/thriftpy,maralla/thriftpy,mariusvniekerk/thriftpy,mariusvniekerk/thriftpy,mariusvniekerk/thriftpy,itnihao/thriftpy,adsharma/flattools,maralla/thriftpy,itnihao/thriftpy,misakwa/thriftpy,keitheis/thriftpy,halfcrazy/thriftpy,halfcrazy/thriftpy,dan-blanchard/thriftpy,adsharma/flattools,OctavianLee/thriftpy,keitheis/thriftpy,duydb2/thriftpy,misakwa/thriftpy,eleme/thriftpy,eleme/thriftpy,OctavianLee/thriftpy,adsharma/flattools,spladug/thriftpy,spladug/thriftpy,misakwa/thriftpy