python检查字符串是否是正确ISBN的方法

时间:2022-06-20 20:33:55

本文实例讲述了python检查字符串是否是正确ISBN的方法。分享给大家供大家参考。具体实现方法如下:

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def isISBN(isbn):
  """Checks if the passed string is a valid ISBN number."""
  if len(isbn) != 10 or not isbn[:9].isdigit():
    return False
  if not (isbn[9].isdigit() or isbn[9].lower() == "x"):
    return False
  tot = sum((10 - i) * int(c) for i, c in enumerate(isbn[:-1]))
  checksum = (11 - tot % 11) % 11
  if isbn[9] == 'X' or isbn[9] == 'x':
    return checksum == 10
  else:
    return checksum == int(isbn[9])
ok = """031234161X 0525949488 076360013X 0671027360 0803612079
    0307263118 0684856093 0767916565 0071392319 1400032806 0765305240"""
for code in ok.split():
  assert isISBN(code)
bad = """0312341613 052594948X 0763600138 0671027364 080361207X 0307263110
     0684856092 0767916567 0071392318 1400032801 0765305241 031234161
     076530Y241 068485609Y"""
for code in bad.split():
  assert not isISBN(code)
print "Tests of isISBN()passed."

希望本文所述对大家的Python程序设计有所帮助。