Encode None as undefined in python_worker
Encode None as undefined in python_worker

MrAlone/mzbench,machinezone/mzbench,timofey-barmin/mzbench,timofey-barmin/mzbench,machinezone/mzbench,MrAlone/mzbench,MrAlone/mzbench,timofey-barmin/mzbench,machinezone/mzbench,timofey-barmin/mzbench,machinezone/mzbench,timofey-barmin/mzbench,machinezone/mzbench,MrAlone/mzbench,MrAlone/mzbench