code: def main():
      parser = optparse.OptionParser(usage="%prog [<root_dir>]")
      (opts, args) = parser.parse_args()
      if len(args) > 1:
          parser.print_help()
          sys.exit(-1)
      elif len(args) == 1:
          root_dir = args[0]
      else:
          root_dir = os.getcwd()
      for dirpath, dirnames, filenames in os.walk(root_dir):
          for fn in filenames:
              if fn.endswith(".pyx"):
                  froot, ext = splitext(fn)
                  cfile = pjoin(dirpath, froot + ".c")
                  if isfile(cfile):
                      touch(cfile)
  
imports: import optparse
  import os
  import sys
  from os.path import isfile, splitext
  from os.path import join
label_desc: Use image node_id 1 for calling a global function with example usage: main() without return types