11.13 Standard Module rfc822

 

This module defines a class, Message, which represents a collection of ``email headers'' as defined by the Internet standard RFC 822. It is used in various contexts, usually to read such headers from a file.

Note that there's a separate module to read Unix, MH, and MMDF style mailbox files: mailbox .

Message (file[, seekable])

A Message instance is instantiated with an open file object as parameter. The optional seekable parameter indicates if the file object is seekable; the default value is 1 for true. Instantiation reads headers from the file up to a blank line and stores them in the instance; after instantiation, the file is positioned directly after the blank line that terminates the headers.

Input lines as read from the file may either be terminated by CR-LF or by a single linefeed; a terminating CR-LF is replaced by a single linefeed before the line is stored.

All header matching is done independent of upper or lower case; e.g. m['From'], m['from'] and m['FROM'] all yield the same result.

parsedate (date)

Attempts to parse a date according to the rules in RFC 822. however, some mailers don't follow that format as specified, so parsedate() tries to guess correctly in such cases. date is a string containing an RFC 822 date, such as 'Mon, 20 Nov 1995 19:12:08 -0500'. If it succeeds in parsing the date, parsedate() returns a 9-tuple that can be passed directly to time.mktime(); otherwise None will be returned.

parsedate_tz (date)

Performs the same function as parsedate(), but returns either None or a 10-tuple; the first 9 elements make up a tuple that can be passed directly to time.mktime(), and the tenth is the offset of the date's timezone from UTC (which is the official term for Greenwich Mean Time). (Note that the sign of the timezone offset is the opposite of the sign of the time.timezone variable for the same timezone; the latter variable follows the POSIX standard while this module follows RFC 822.) If the input string has no timezone, the last element of the tuple returned is None.

mktime_tz (tuple)

Turn a 10-tuple as returned by parsedate_tz() into a UTC timestamp. It the timezone item in the tuple is None, assume local time. Minor deficiency: this first interprets the first 8 elements as a local time and then compensates for the timezone difference; this may yield a slight error around daylight savings time switch dates. Not enough to worry about for common use.