import re
daterange_re = "\\b((?P<monthdayX>(?P<monthAX>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)[,\\s]+(?P<dayAX>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?(?P<AX>)|(?P<dayBX>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?[,\\s]+(?P<monthBX>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)(?P<BX>))((?P<dashX>\\s*(-+|&+|,|and|to|until|thru|through|\\.\\s*(\\.\\s*)+)\\s*)(?P<monthday2X>(?P<monthA2X>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)[,\\s]+(?P<dayA2X>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?(?P<A2X>)|(?P<dayB2X>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?[,\\s]+(?P<monthB2X>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)(?P<B2X>)))?(?P<X>)|(?P<monthY>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)\\s+(?P<dayrangeY>(?P<dayY>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?(?P<dashY>\\s*(-+|&+|,|and|to|until|thru|through|\\.\\s*(\\.\\s*)+)\\s*)(?P<day2Y>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?)(?P<Y>)|(?P<dayrangeZ>(?P<dayZ>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?(?P<dashZ>\\s*(-+|&+|,|and|to|until|thru|through|\\.\\s*(\\.\\s*)+)\\s*)(?P<day2Z>\\d|[12]\\d|3[01])(?:[-\\s]*(?:st|nd|rd|th))?)\\s+(?P<monthZ>jan|january|feb|february|mar|march|apr|april|may|jun|june|jul|july|aug|august|sep|sept|september|oct|october|nov|november|dec|december)(?P<Z>))(\\s+|\\s*[,.]\\s*)(?P<year>\\d\\d\\d\\d|'?\\d\\d)((?=\\D)|$)"
## The following line segfaults:
re.compile (daterange_re, re.IGNORECASE).match ('December 20, 1997')