Subzero: Print defaults as appropriate in python script help text.

pydir/szbuild.py

 #!/usr/bin/env python2
 
 import argparse
 import os
 import pipes
 import re
 import sys
 
 from utils import shellcmd
 from utils import FindBaseNaCl
@@ skipping 90 matching lines @@
     argparser.add_argument('--include', '-i', default=[], dest='include',
                            action='append',
                            help='Subzero symbols to include ' +
                                 '(regex or line range)')
     argparser.add_argument('--exclude', '-e', default=[], dest='exclude',
                            action='append',
                            help='Subzero symbols to exclude ' +
                                 '(regex or line range)')
     argparser.add_argument('--output', '-o', default='a.out', dest='output',
                            action='store',
-                           help='Output executable (default a.out)')
+                           help='Output executable. Default %(default)s.')
     argparser.add_argument('-O', default='2', dest='optlevel',
                            choices=['m1', '-1', '0', '1', '2'],
                            help='Optimization level ' +
-                                '(m1 and -1 are equivalent)')
+                                '(m1 and -1 are equivalent).' +
+                                ' Default %(default)s.')
     argparser.add_argument('--verbose', '-v', dest='verbose',
                            action='store_true',
                            help='Display some extra debugging output')
     args = argparser.parse_args()
 
     pexe = args.pexe
     [pexe_base, ext] = os.path.splitext(pexe)
     if ext != '.pexe':
         pexe_base = pexe
     pexe_base_unescaped = pexe_base
@@ skipping 104 matching lines @@
     # Put the extra verbose printing at the end.
     if args.verbose:
         print 'PATH={path}'.format(path=os.environ['PATH'])
         print 'include={regex}'.format(regex=re_include_str)
         print 'exclude={regex}'.format(regex=re_exclude_str)
         print 'default_match={dm}'.format(dm=default_match)
         print 'Number of Subzero syms = {num}'.format(num=len(sz_syms))
 
 if __name__ == '__main__':
     main()