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：
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。