code: def quote_str(obj):
      r
      if not isinstance(obj, str):
          return obj
      return "'{obj}'".format(obj=obj) if '"' in obj else '"{obj}"'.format(obj=obj)
docs: r"""
      Add extra quotes to a string.
  
      If the argument is not a string it is returned unmodified.
  
      :param obj: Object
      :type  obj: any
  
      :rtype: Same as argument
  
      For example:
  
          >>> import pmisc
          >>> pmisc.quote_str(5)
          5
          >>> pmisc.quote_str('Hello!')
          '"Hello!"'
          >>> pmisc.quote_str('He said "hello!"')
          '\'He said "hello!"\''