text: #! /usr/bin/env python3
  """Create a TAGS file for Python programs, usable with GNU Emacs.
  
  usage: eptags pyfiles...
  
  The output TAGS file is usable with Emacs version 18, 19, 20.
  Tagged are:
   - functions (even inside other defs or classes)
   - classes
  
  eptags warns about files it cannot open.
  eptags will not give warnings about duplicate tags.
  
  BUGS:
     Because of tag duplication (methods with the same name in different
     classes), TAGS files are not very useful for most object-oriented
     python projects.
  """
  import sys,re
  
  expr = r'^[ \t]*(def|class)[ \t]+([a-zA-Z_][a-zA-Z0-9_]*)[ \t]*[:\(]'
  matcher = re.compile(expr)
  
  def treat_file(filename, outfp):
      """Append tags found in file named 'filename' to the open file 'outfp'"""
      try:
          fp = open(filename, 'r')
      except OSError:
          sys.stderr.write('Cannot open %s\n'%filename)
          return
      charno = 0
      lineno = 0
      tags = []
      size = 0
      while 1:
          line = fp.readline()
          if not line:
              break
          lineno = lineno + 1
          m = matcher.search(line)
          if m:
              tag = m.group(0) + '\177%d,%d\n' % (lineno, charno)
              tags.append(tag)
              size = size + len(tag)
          charno = charno + len(line)
      outfp.write('\f\n%s,%d\n' % (filename,size))
      for tag in tags:
          outfp.write(tag)
  
  def main():
      outfp = open('TAGS', 'w')
      for filename in sys.argv[1:]:
          treat_file(filename, outfp)
  
  if __name__=="__main__":
      main()
  