commas missing in locateID.py

18k1-colesmp1:~/Documents/MATH152_Jan2020/1bMATH152Jan30/idReader>python3 locateID.py File "locateID.py", line 102 cmd = ["python3" "./readStudentID.py" str(t) str(b)] ^ SyntaxError: invalid syntax

needs commas: ["python3" "./readStudentID.py" str(t) str(b)]

where => ,