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(python2.1-lib.info)rfc822

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Parse RFC 822 mail headers
==========================

Parse RFC 822 style mail headers.

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.
This module also defines a helper class `AddressList' for parsing RFC
822 addresses.  Please refer to the RFC for information on the specific
syntax of RFC 822 headers.

The `mailbox'  module provides classes to read mailboxes produced by
various end-user mail programs.

`Message(file[, seekable])'
     A `Message' instance is instantiated with an input object as
     parameter.  Message relies only on the input object having a
     `readline()' method; in particular, ordinary file objects qualify.
     Instantiation reads headers from the input object up to a
     delimiter line (normally a blank line) and stores them in the
     instance.  The message body, following the headers, is not
     consumed.

     This class can work with any input object that supports a
     `readline()' method.  If the input object has seek and tell
     capability, the `rewindbody()' method will work; also, illegal
     lines will be pushed back onto the input stream.  If the input
     object lacks seek but has an `unread()' method that can push back a
     line of input, `Message' will use that to push back illegal lines.
     Thus this class can be used to parse messages coming from a
     buffered stream.

     The optional SEEKABLE argument is provided as a workaround for
     certain stdio libraries in which `tell()' discards buffered data
     before discovering that the `lseek()' system call doesn't work.
     For maximum portability, you should set the seekable argument to
     zero to prevent that initial `tell()' when passing in an
     unseekable object such as a a file object created from a socket
     object.

     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.

`AddressList(field)'
     You may instantiate the `AddressList' helper class using a single
     string parameter, a comma-separated list of RFC 822 addresses to be
     parsed.  (The parameter `None' yields an empty list.)

`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.  Note that
     fields 6, 7, and 8 of the result tuple are not usable.

`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'.
     Note that fields 6, 7, and 8 of the result tuple are not usable.

`mktime_tz(tuple)'
     Turn a 10-tuple as returned by `parsedate_tz()' into a UTC
     timestamp.  If 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.

See also:
     Note: mailbox Classes to read various mailbox formats produced
     by end-user mail programs.  Note: mimetools Subclass of
     rfc.Message that handles MIME encoded messages.

Message Objects

AddressList Objects