code: def shlex_split(s, sep):
      
      lex = shlex.shlex(s, posix=True)
      lex.whitespace = sep
      lex.whitespace_split = True
      return [l for l in lex]
docs: Split a character on the given set of characters.
  
      Example::
  
          >>> shlex_split('foo,bar', ', ')
          ['foo', 'bar']
          >>> shlex_split('foo\\\\,bar1', ',')  # escape a separator
          ['foo,bar1']
          >>> shlex_split('"foo,bar", bla', ', ')
          ['foo,bar', 'bla']
          >>> shlex_split('foo,"bar,bla"', ',')
          ['foo', 'bar,bla']