<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def main():
 """ Testing function for DFA brzozowski algebraic method Operation """

    argv = sys.argv
    if len(argv) < 2:
        targetfile = 'target.y'
    else:
        targetfile = argv[1]
    print 'Parsing ruleset: ' + targetfile,
    flex_a = Flexparser()
    mma = flex_a.yyparse(targetfile)
    print 'OK'
    print 'Perform minimization on initial automaton:',
    mma.minimize()
    print 'OK'
    print 'Perform Brzozowski on minimal automaton:',
    brzozowski_a = Brzozowski(mma)
    mma_regex = brzozowski_a.get_regex()
    print mma_regex