""" This module provides a set of constructors and routines to convert between DateTime[Delta] instances and ARPA representations of date and time. The format is specified by RFC822 + RFC1123. (c) 1998, Copyright Marc-Andre Lemburg; All Rights Reserved. See the documentation for further information on copyrights, or contact the author (mal@lemburg.com). """ import DateTime import re,string # Grammar: RFC822 + RFC1123 + depreciated RFC850 _litday = '(?PMon|Tue|Wed|Thu|Fri|Sat|Sun)[a-z]*' _litmonth = '(?PJan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)'\ '[a-z]*' _date = ('(?:(?P\d?\d)(?: +' + _litmonth + ' +|-(?P\d?\d)-)(?P(?:\d\d)?\d\d))') _zone = ('(?PUT|UTC|GMT|EST|EDT|CST|CDT|MST|MDT|PST|PDT|' '[A-Z]|[+-]\d\d\d\d)') _time = ('(?:(?P\d\d):(?P\d\d)' '(?::(?P\d\d))?(?: +'+_zone+')?)') # Timezone information is made optional because some mail apps # forget to add it (most of these seem to be spamming engines, btw). # It defaults to UTC. _datetime = '(?:'+ _litday + ', )? *' + _date + ' +' + _time # + '$' # We are not strict on the extra characters: some applications # add extra information to the date header field. Additional spaces # between the fields and extra characters in the literal day # and month fields are also silently ignored. _arpadatetime = re.compile(_datetime) # Translation tables _daytable = {'Mon':0, 'Tue':1, 'Wed':2, 'Thu':3, 'Fri':4, 'Sat':5, 'Sun':6 } _monthtable = {'Jan':1, 'Feb':2, 'Mar':3, 'Apr':4, 'May':5, 'Jun':6, 'Jul':7, 'Aug':8, 'Sep':9, 'Oct':10, 'Nov':11, 'Dec':12 } _days = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] _months = [None, 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ] _zonetable = {# Standards 'UT':0, 'UTC':0, 'GMT':0, # US time zones (normal + dst) 'AST':-4, 'ADT':-3, 'EST':-5, 'EDT':-4, 'CST':-6, 'CDT':-5, 'MST':-7, 'MDT':-6, 'PST':-8, 'PDT':-7, # US military time zones 'Z': 0, 'A': 1, 'B': 2, 'C': 3, 'D': 4, 'E': 5, 'F': 6, 'G': 7, 'H': 8, 'I': 9, 'K': 10, 'L': 11, 'M': 12, 'N':-1, 'O':-2, 'P':-3, 'Q':-4, 'R':-5, 'S':-6, 'T':-7, 'U':-8, 'V':-9, 'W':-10, 'X':-11, 'Y':-12 } _zoneoffset = re.compile('(?P[+-])(?P\d\d\d\d)') def _utc_offset(zone, atoi=string.atoi): """ Return the UTC time zone offset as DateTimeDelta instance. """ if zone is None: return 0 if _zonetable.has_key(zone): return _zonetable[zone]*DateTime.oneHour offset = _zoneoffset.match(zone) if not offset: raise ValueError,'wrong format or unkown time zone -- use +-HHMM' sign,value = offset.groups() value = atoi(value[:2])*60 + atoi(value[3:]) if sign == '-': value = -value return value*DateTime.oneMinute def ParseDateTime(arpastring, strip=string.strip,atoi=string.atoi,atof=string.atof): """ParseDateTime(arpastring) Returns a DateTime instance reflecting the given ARPA date assuming it is local time (timezones are silently ignored).""" s = strip(arpastring) date = _arpadatetime.match(s) if not date: raise ValueError,'wrong format or unkown time zone' litday,day,litmonth,month,year,hour,minute,second,zone = date.groups() if len(year) == 2: year = 1900 + atoi(year) else: year = atoi(year) if litmonth: try: month = _monthtable[litmonth] except KeyError: raise ValueError,'wrong month format' else: month = atoi(month) day = atoi(day) hour = atoi(hour) minute = atoi(minute) if second is None: second = 0.0 else: second = atof(second) # litday and timezone are ignored return DateTime.DateTime(year,month,day,hour,minute,second) def ParseDateTimeGMT(arpastring, strip=string.strip,atoi=string.atoi,atof=string.atof): """ParseDateTimeGMT(arpastring) Returns a DateTime instance reflecting the given ARPA date converting it to UTC (timezones are honored).""" s = strip(arpastring) date = _arpadatetime.match(s) if not date: raise ValueError,'wrong format or unkown time zone' litday,day,litmonth,month,year,hour,minute,second,zone = date.groups() if len(year) == 2: year = 1900 + atoi(year) else: year = atoi(year) if litmonth: try: month = _monthtable[litmonth] except KeyError: raise ValueError,'wrong month format' else: month = atoi(month) day = atoi(day) hour = atoi(hour) minute = atoi(minute) if second is None: second = 0.0 else: second = atof(second) offset = _utc_offset(zone) # litday is ignored return DateTime.DateTime(year,month,day,hour,minute,second) - offset # Alias ParseDateTimeUTC = ParseDateTimeGMT def str(datetime,tz=None, # Locals: tz_offset=DateTime.tz_offset): """str(datetime,tz=DateTime.tz_offset(datetime)) Returns the datetime instance as ARPA date string. tz can be given as DateTimeDelta instance providing the time zone difference from datetime's zone to UTC. It defaults to DateTime.tz_offset(datetime) which assumes local time. """ if tz is None: tz = tz_offset(datetime) return '%s, %02i %s %04i %02i:%02i:%02i %+03i%02i' % ( _days[datetime.day_of_week], datetime.day, _months[datetime.month], datetime.year, datetime.hour, datetime.minute, datetime.second, tz.hour,tz.minute) def strGMT(datetime): """ strGMT(datetime) Returns the datetime instance as ARPA date string assuming it is given in UTC. """ return '%s, %02i %s %04i %02i:%02i:%02i GMT' % ( _days[datetime.day_of_week], datetime.day, _months[datetime.month], datetime.year, datetime.hour, datetime.minute, datetime.second) # Alias strUTC = strGMT def _test(): import sys, os, rfc822 file = os.path.join(os.environ['HOME'], 'nsmail/Inbox') f = open(file, 'r') while 1: m = rfc822.Message(f) if not m: break print 'From:', m.getaddr('from') print 'To:', m.getaddrlist('to') print 'Subject:', m.getheader('subject') raw = m.getheader('date') try: date = ParseDateTimeUTC(raw) print 'Date:',strUTC(date) except ValueError,why: print 'PROBLEMS:',repr(raw),'-->',why raw_input('...hit return to continue') print # Netscape mail file while 1: line = f.readline() if line[:6] == 'From -': break if __name__ == '__main__': _test()