1 """ This module provides a set of constructors and routines to convert

     2     between DateTime[Delta] instances and ARPA representations of date

     3     and time. The format is specified by RFC822 + RFC1123.

     4 

     5     Note: Timezones are only interpreted by ParseDateTimeGMT(). All

     6     other constructors silently ignore the time zone information.

     7 

     8     Copyright (c) 1998-2000, Marc-Andre Lemburg; mailto:mal@lemburg.com

     9     Copyright (c) 2000-2007, eGenix.com Software GmbH; mailto:info@egenix.com

    10     See the documentation for further information on copyrights,

    11     or contact the author. All Rights Reserved.

    12 

    13 """

    14 import DateTime,Timezone

    15 import re,string

    16 

    17 # Grammar: RFC822 + RFC1123 + depreciated RFC850

    18 _litday = '(?P<litday>Mon|Tue|Wed|Thu|Fri|Sat|Sun)[a-z]*'

    19 _litmonth = '(?P<litmonth>Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)'\

    20             '[a-z]*'

    21 _date = ('(?:(?P<day>\d?\d)(?: +' + _litmonth + 

    22          ' +|-(?P<month>\d?\d)-)(?P<year>(?:\d\d)?\d\d))')

    23 _zone = Timezone.zone

    24 _time = ('(?:(?P<hour>\d\d):(?P<minute>\d\d)'

    25          '(?::(?P<second>\d\d))?(?: +'+_zone+')?)')

    26 #       Timezone information is made optional because some mail apps

    27 #       forget to add it (most of these seem to be spamming engines, btw).

    28 #       It defaults to UTC.

    29 

    30 _arpadate = '(?:'+ _litday + ',? )? *' + _date

    31 _arpadatetime = '(?:'+ _litday + ',? )? *' + _date + ' +' + _time

    32 

    33 #       We are not strict about the extra characters: some applications

    34 #       add extra information to the date header field. Additional spaces

    35 #       between the fields and extra characters in the literal day

    36 #       and month fields are also silently ignored.

    37 

    38 arpadateRE = re.compile(_arpadate)

    39 arpadatetimeRE = re.compile(_arpadatetime)

    40 

    41 # Translation tables

    42 litdaytable = {'mon':0, 'tue':1, 'wed':2, 'thu':3, 'fri':4, 'sat':5, 'sun':6 }

    43 litmonthtable = {'jan':1, 'feb':2, 'mar':3, 'apr':4, 'may':5, 'jun':6,

    44                  'jul':7, 'aug':8, 'sep':9, 'oct':10, 'nov':11, 'dec':12 }

    45 _days = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']

    46 _months = [None, 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',

    47                  'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ]

    48 

    49 def ParseDate(arpastring,parse_arpadate=arpadateRE.match,

    50 

    51               strip=string.strip,atoi=string.atoi,atof=string.atof,

    52               lower=string.lower):

    53 

    54     """ParseDate(arpastring)

    55 

    56        Returns a DateTime instance reflecting the given ARPA

    57        date. Only the date part is parsed, any time part will be

    58        ignored. The instance's time is set to 0:00:00.

    59 

    60     """

    61     s = strip(arpastring)

    62     date = parse_arpadate(s)

    63     if not date:

    64         raise ValueError,'wrong format'

    65     litday,day,litmonth,month,year = date.groups()

    66     if len(year) == 2:

    67         year = DateTime.add_century(atoi(year))

    68     else:

    69         year = atoi(year)

    70     if litmonth:

    71         litmonth = lower(litmonth)

    72         try:

    73             month = litmonthtable[litmonth]

    74         except KeyError:

    75             raise ValueError,'wrong month format'

    76     else:

    77         month = atoi(month)

    78     day = atoi(day)

    79     # litday and timezone are ignored

    80     return DateTime.DateTime(year,month,day)

    81 

    82 def ParseDateTime(arpastring,parse_arpadatetime=arpadatetimeRE.match,

    83 

    84                   strip=string.strip,atoi=string.atoi,atof=string.atof,

    85                   lower=string.lower):

    86 

    87     """ParseDateTime(arpastring)

    88 

    89        Returns a DateTime instance reflecting the given ARPA date assuming

    90        it is local time (timezones are silently ignored).

    91     """

    92     s = strip(arpastring)

    93     date = parse_arpadatetime(s)

    94     if not date:

    95         raise ValueError,'wrong format or unknown time zone'

    96     litday,day,litmonth,month,year,hour,minute,second,zone = date.groups()

    97     if len(year) == 2:

    98         year = DateTime.add_century(atoi(year))

    99     else:

   100         year = atoi(year)

   101     if litmonth:

   102         litmonth = lower(litmonth)

   103         try:

   104             month = litmonthtable[litmonth]

   105         except KeyError:

   106             raise ValueError,'wrong month format'

   107     else:

   108         month = atoi(month)

   109     day = atoi(day)

   110     hour = atoi(hour)

   111     minute = atoi(minute)

   112     if second is None:

   113         second = 0.0

   114     else:

   115         second = atof(second)

   116     # litday and timezone are ignored

   117     return DateTime.DateTime(year,month,day,hour,minute,second)

   118 

   119 def ParseDateTimeGMT(arpastring,parse_arpadatetime=arpadatetimeRE.match,

   120 

   121                      strip=string.strip,atoi=string.atoi,atof=string.atof,

   122                      lower=string.lower):

   123 

   124     """ParseDateTimeGMT(arpastring)

   125 

   126        Returns a DateTime instance reflecting the given ARPA date converting

   127        it to UTC (timezones are honored).

   128     """

   129     s = strip(arpastring)

   130     date = parse_arpadatetime(s)

   131     if not date:

   132         raise ValueError,'wrong format or unknown time zone'

   133     litday,day,litmonth,month,year,hour,minute,second,zone = date.groups()

   134     if len(year) == 2:

   135         year = DateTime.add_century(atoi(year))

   136     else:

   137         year = atoi(year)

   138     if litmonth:

   139         litmonth = lower(litmonth)

   140         try:

   141             month = litmonthtable[litmonth]

   142         except KeyError:

   143             raise ValueError,'wrong month format'

   144     else:

   145         month = atoi(month)

   146     day = atoi(day)

   147     hour = atoi(hour)

   148     minute = atoi(minute)

   149     if second is None:

   150         second = 0.0

   151     else:

   152         second = atof(second)

   153     offset = Timezone.utc_offset(zone)

   154     # litday is ignored

   155     return DateTime.DateTime(year,month,day,hour,minute,second) - offset

   156 

   157 # Alias

   158 ParseDateTimeUTC = ParseDateTimeGMT

   159 

   160 def str(datetime,tz=None):

   161 

   162     """str(datetime,tz=DateTime.tz_offset(datetime))

   163 

   164     Returns the datetime instance as ARPA date string. tz can be given

   165     as DateTimeDelta instance providing the time zone difference from

   166     datetime's zone to UTC. It defaults to

   167     DateTime.tz_offset(datetime) which assumes local time. """

   168 

   169     if tz is None:

   170         tz = datetime.gmtoffset()

   171     return '%s, %02i %s %04i %02i:%02i:%02i %+03i%02i' % (

   172         _days[datetime.day_of_week], datetime.day, 

   173         _months[datetime.month], datetime.year,

   174         datetime.hour, datetime.minute, datetime.second,

   175         tz.hour,tz.minute)

   176 

   177 def strGMT(datetime):

   178 

   179     """ strGMT(datetime)

   180 

   181     Returns the datetime instance as ARPA date string assuming it

   182     is given in GMT. """

   183 

   184     return '%s, %02i %s %04i %02i:%02i:%02i GMT' % (

   185         _days[datetime.day_of_week], datetime.day, 

   186         _months[datetime.month], datetime.year,

   187         datetime.hour, datetime.minute, datetime.second)

   188 

   189 def strUTC(datetime):

   190 

   191     """ strUTC(datetime)

   192 

   193     Returns the datetime instance as ARPA date string assuming it

   194     is given in UTC. """

   195 

   196     return '%s, %02i %s %04i %02i:%02i:%02i UTC' % (

   197         _days[datetime.day_of_week], datetime.day, 

   198         _months[datetime.month], datetime.year,

   199         datetime.hour, datetime.minute, datetime.second)

   200 

   201 def _test():

   202     import sys, os, rfc822

   203     file = os.path.join(os.environ['HOME'], 'nsmail/Inbox')

   204     f = open(file, 'r')

   205     while 1:

   206         m = rfc822.Message(f)

   207         if not m:

   208             break

   209         print 'From:', m.getaddr('from')

   210         print 'To:', m.getaddrlist('to')

   211         print 'Subject:', m.getheader('subject')

   212         raw = m.getheader('date')

   213         try:

   214             date = ParseDateTimeUTC(raw)

   215             print 'Date:',strUTC(date)

   216         except ValueError,why:

   217             print 'PROBLEMS:',repr(raw),'-->',why

   218             raw_input('...hit return to continue')

   219         print

   220         # Netscape mail file

   221         while 1:

   222             line = f.readline()

   223             if line[:6] == 'From -':

   224                 break

   225 

   226 if __name__ == '__main__':

   227     _test()