Python 正则表达式错误字符范围。

Question

我正在使用以下正则表达式来匹配不同的日期模式。它在 regex101.com 中运行良好。但是当我导入到 python 时，出现“错误字符范围”异常。

  pattern = ur"((?:\b((?:(january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)['\s\.]{0,4}(?:\d{4}|\d{2})|(?:january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)|((?:0[1-9]|[1-3][0-9]|[0-9])/(?:0[1-9]|[1-3][0-9])/(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9]))|((?:0[1-9]|1[0-2]|[1-9])\s{0,3}[-/']{1,3}[\s-/']{0,3}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))))(?:(?![\r\n])\s){0,4})[-/–to]{0,2}(?:(?![\r\n])\s){0,4}(((?:january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)[-'\s\.]{0,4}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))|((?:0[1-9]|[1-3][0-9]|[1-9])/(?:0[1-9]|[1-3][0-9])/(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))|((?:0[1-9]|1[0-2]|[1-9])\s{0,3}[-/']{1,3}[\s-/']{0,3}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9]))))))"

  https://regex101.com/r/rU3cE9/1

Answer 1

问题主要是因为 [\s-/'] 字符类中存在连字符，因此 Python 将其解释为字符间隔(如 [a-z] ).我建议您将连字符放在字符类 [-\s/'] 中的第一个或最后一个位置或将其转义，以防止歧义。

>>> reg = re.compile(ur"((?:\b((?:(january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)['\s\.]{0,4}(?:\d{4}|\d{2})|(?:january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)|((?:0[1-9]|[1-3][0-9]|[0-9])/(?:0[1-9]|[1-3][0-9])/(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9]))|((?:0[1-9]|1[0-2]|[1-9])\s{0,3}[-/']{1,3}[-\s/']{0,3}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))))(?:(?![\r\n])\s){0,4})[-/to–]{0,2}(?:(?![\r\n])\s){0,4}(((?:january|jan|february|feb|march|mar|april|apr|may|jun|june|july|jul|august|aug|september|set|sep|october|oct|november|nov|december|dec)[-'\s\.]{0,4}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))|((?:0[1-9]|[1-3][0-9]|[1-9])/(?:0[1-9]|[1-3][0-9])/(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9])))|((?:0[1-9]|1[0-2]|[1-9])\s{0,3}[-/']{1,3}[-\s/']{0,3}(?:(19[7-9][0-9])|(20[0-1][0-9])|([7-9][0-9]|[0-1][0-9]))))))")
>>>