Cleanup grade.py.
Cleanup grade.py.

PEP8 style plus some reorganization to avoid unnecessary calls to
sys.argv

trainman419/cnc-grader,trainman419/cnc-grader,trainman419/cnc-grader,trainman419/cnc-grader,trainman419/cnc-grader,trainman419/cnc-grader,trainman419/cnc-grader