code: def main():
      parser = argparse.ArgumentParser()
      parser.add_argument("--exclude", nargs="+")
      parser.add_argument("dir")
      args = parser.parse_args()
  
      n_err = 0
  
      for dir, _, files in os.walk(args.dir):
          for file in files:
              _, ext = os.path.splitext(file)
              if not ext == ".py":
                  continue
  
              if args.exclude is not None and file in args.exclude:
                  continue
  
              path = os.path.join(dir, file)
              lines = open(path).readlines()
  
              for lineno, msg in check("".join(lines)):
                  print("{:s}:{:d} : {:s}".format(path, lineno, msg))
                  print(lines[lineno - 1])
  
                  n_err += 1
  
      if n_err > 0:
          sys.exit("{:d} style errors are found.".format(n_err))
  
file_path: chainercv/style_checker.py
imports: import argparse
  import ast
  import os
  import sys
label_desc: Use image node_id 7 for calling a global function with example usage: main() without return types