old_contents: # default separator (whitespace)
  print("a b".rsplit())
  #print("   a   b    ".rsplit(None))
  #print("   a   b    ".rsplit(None, 1))
  #print("   a   b    ".rsplit(None, 2))
  #print("   a   b  c  ".rsplit(None, 1))
  #print("   a   b  c  ".rsplit(None, 0))
  #print("   a   b  c  ".rsplit(None, -1))
  
  # empty separator should fail (this actually delegates to .split())
  try:
      "abc".rsplit('')
  except ValueError:
      print("ValueError")
  
  # empty separator should fail (error handled in .rsplit())
  try:
      'a a a a'.rsplit('', 5)
  except ValueError:
      print('ValueError')
  
  # bad separator type
  try:
      'a a a a'.rsplit(1)
  except TypeError:
      print('TypeError')
  
  # non-empty separator
  print("abc".rsplit("a"))
  print("abc".rsplit("b"))
  print("abc".rsplit("c"))
  print("abc".rsplit("z"))
  print("abc".rsplit("ab"))
  print("abc".rsplit("bc"))
  print("abc".rsplit("abc"))
  print("abc".rsplit("abcd"))
  print("abcabc".rsplit("bc"))
  print("abcabc".rsplit("bc", 0))
  print("abcabc".rsplit("bc", 1))
  print("abcabc".rsplit("bc", 2))
  
  print("10/11/12".rsplit("/", 1))
  print("10/11/12".rsplit("/", 2))
  print("10/11/12".rsplit("/", 3))
  print("10/11/12".rsplit("/", 4))
  print("10/11/12".rsplit("/", 5))
  
  print("/*10/*11/*12/*".rsplit("/*", 1))
  print("/*10/*11/*12/*".rsplit("/*", 2))
  print("/*10/*11/*12/*".rsplit("/*", 3))
  print("/*10/*11/*12/*".rsplit("/*", 4))
  print("/*10/*11/*12/*".rsplit("/*", 5))
  
  print(b"abcabc".rsplit(b"bc", 2))
  
new_contents: # default separator (whitespace)
  print("a b".rsplit())
  #print("   a   b    ".rsplit(None))
  #print("   a   b    ".rsplit(None, 1))
  #print("   a   b    ".rsplit(None, 2))
  #print("   a   b  c  ".rsplit(None, 1))
  #print("   a   b  c  ".rsplit(None, 0))
  #print("   a   b  c  ".rsplit(None, -1))
  
  # empty separator should fail (this actually delegates to .split())
  try:
      "abc".rsplit('')
  except ValueError:
      print("ValueError")
  
  # empty separator should fail (error handled in .rsplit())
  try:
      'a a a a'.rsplit('', 5)
  except ValueError:
      print('ValueError')
  
  # bad separator type
  try:
      'a a a a'.rsplit(1)
  except TypeError:
      print('TypeError')
  
  # non-empty separator
  print("abc".rsplit("a"))
  print("abc".rsplit("b"))
  print("abc".rsplit("c"))
  print("abc".rsplit("z"))
  print("abc".rsplit("ab"))
  print("abc".rsplit("bc"))
  print("abc".rsplit("abc"))
  print("abc".rsplit("abcd"))
  print("abcabc".rsplit("bc"))
  print("abcabc".rsplit("bc", 0))
  print("abcabc".rsplit("bc", 1))
  print("abcabc".rsplit("bc", 2))
  
  print("10/11/12".rsplit("/", 1))
  print("10/11/12".rsplit("/", 2))
  print("10/11/12".rsplit("/", 3))
  print("10/11/12".rsplit("/", 4))
  print("10/11/12".rsplit("/", 5))
  
  print("/*10/*11/*12/*".rsplit("/*", 1))
  print("/*10/*11/*12/*".rsplit("/*", 2))
  print("/*10/*11/*12/*".rsplit("/*", 3))
  print("/*10/*11/*12/*".rsplit("/*", 4))
  print("/*10/*11/*12/*".rsplit("/*", 5))
  
  print(b"abcabc".rsplit(b"bc", 2))
  
  # negative "maxsplit" should delegate to .split()
  print('abaca'.rsplit('a', -1))
  print('abaca'.rsplit('a', -2))
  
subject: Add tests for negative "maxsplit" argument.