code: def unescape(s):
    
    assert isinstance(s, basestring)
    s = s.replace('\t', ',')
    s = s.replace('\\,', ',')
    s = s.replace('\\n', '\n')
    s = s.replace('\\\\', '\\')
  
    return s
docs: Unescapes a string that may contain commas, tabs, newlines and dashes
  
    Commas are decoded from tabs.
  
    :param s: (string) to unescape
    :returns: (string) unescaped string