The email package version 1.0, prototyped as mimelib

<http://sf.net/projects/mimelib>.  There /are/ API differences between
mimelib and email, but most of the implementations are shared (except
where cool Py2.2 stuff like generators are used).

12 files changed, 1302 insertions, 0 deletions

diff --git a/Lib/email/Encoders.py b/Lib/email/Encoders.py
new file mode 100644
index 0000000..36db370
--- /dev/null
+++ b/Lib/email/Encoders.py
@@ -0,0 +1,68 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Module containing encoding functions for Image.Image and Text.Text.
+"""
+
+import base64
+from quopri import encodestring as _encodestring
+
+
+
+# Helpers
+def _qencode(s):
+    return _encodestring(s, quotetabs=1)
+
+def _bencode(s):
+    # We can't quite use base64.encodestring() since it tacks on a "courtesy
+    # newline".  Blech!
+    if not s:
+        return s
+    hasnewline = (s[-1] == '\n')
+    value = base64.encodestring(s)
+    if not hasnewline and value[-1] == '\n':
+        return value[:-1]
+    return value
+
+
+
+def encode_base64(msg):
+    """Encode the message's payload in Base64.
+
+    Also, add an appropriate Content-Transfer-Encoding: header.
+    """
+    orig = msg.get_payload()
+    encdata = _bencode(orig)
+    msg.set_payload(encdata)
+    msg['Content-Transfer-Encoding'] = 'base64'
+
+
+
+def encode_quopri(msg):
+    """Encode the message's payload in Quoted-Printable.
+
+    Also, add an appropriate Content-Transfer-Encoding: header.
+    """
+    orig = msg.get_payload()
+    encdata = _qencode(orig)
+    msg.set_payload(encdata)
+    msg['Content-Transfer-Encoding'] = 'quoted-printable'
+
+
+
+def encode_7or8bit(msg):
+    """Set the Content-Transfer-Encoding: header to 7bit or 8bit."""
+    orig = msg.get_payload()
+    # We play a trick to make this go fast.  If encoding to ASCII succeeds, we
+    # know the data must be 7bit, otherwise treat it as 8bit.
+    try:
+        orig.encode('ascii')
+    except UnicodeError:
+        msg['Content-Transfer-Encoding'] = '8bit'
+    else:
+        msg['Content-Transfer-Encoding'] = '7bit'
+
+
+
+def encode_noop(msg):
+    """Do nothing."""
diff --git a/Lib/email/Errors.py b/Lib/email/Errors.py
new file mode 100644
index 0000000..71d7663
--- /dev/null
+++ b/Lib/email/Errors.py
@@ -0,0 +1,26 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""email package exception classes.
+"""
+
+
+
+class MessageError(Exception):
+    """Base class for errors in this module."""
+
+
+class MessageParseError(MessageError):
+    """Base class for message parsing errors."""
+
+
+class HeaderParseError(MessageParseError):
+    """Error while parsing headers."""
+
+
+class BoundaryError(MessageParseError):
+    """Couldn't find terminating boundary."""
+
+
+class MultipartConversionError(MessageError, TypeError):
+    """Conversion to a multipart is prohibited."""
diff --git a/Lib/email/Generator.py b/Lib/email/Generator.py
new file mode 100644
index 0000000..ca9757f
--- /dev/null
+++ b/Lib/email/Generator.py
@@ -0,0 +1,326 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Classes to generate plain text from a message object tree.
+"""
+
+import time
+import re
+import random
+
+from types import ListType, StringType
+from cStringIO import StringIO
+
+# Intrapackage imports
+import Message
+import Errors
+
+SEMISPACE = '; '
+BAR = '|'
+UNDERSCORE = '_'
+NL = '\n'
+SEMINLTAB = ';\n\t'
+SPACE8 = ' ' * 8
+
+fcre = re.compile(r'^From ', re.MULTILINE)
+
+
+
+class Generator:
+    """Generates output from a Message object tree.
+
+    This basic generator writes the message to the given file object as plain
+    text.
+    """
+    #
+    # Public interface
+    #
+
+    def __init__(self, outfp, mangle_from_=1, maxheaderlen=78):
+        """Create the generator for message flattening.
+
+        outfp is the output file-like object for writing the message to.  It
+        must have a write() method.
+
+        Optional mangle_from_ is a flag that, when true, escapes From_ lines
+        in the body of the message by putting a `>' in front of them.
+
+        Optional maxheaderlen specifies the longest length for a non-continued
+        header.  When a header line is longer (in characters, with tabs
+        expanded to 8 spaces), than maxheaderlen, the header will be broken on
+        semicolons and continued as per RFC 2822.  If no semicolon is found,
+        then the header is left alone.  Set to zero to disable wrapping
+        headers.  Default is 78, as recommended (but not required by RFC
+        2822.
+        """
+        self._fp = outfp
+        self._mangle_from_ = mangle_from_
+        self.__first = 1
+        self.__maxheaderlen = maxheaderlen
+
+    def write(self, s):
+        # Just delegate to the file object
+        self._fp.write(s)
+
+    def __call__(self, msg, unixfrom=0):
+        """Print the message object tree rooted at msg to the output file
+        specified when the Generator instance was created.
+
+        unixfrom is a flag that forces the printing of a Unix From_ delimiter
+        before the first object in the message tree.  If the original message
+        has no From_ delimiter, a `standard' one is crafted.  By default, this
+        is 0 to inhibit the printing of any From_ delimiter.
+
+        Note that for subobjects, no From_ line is printed.
+        """
+        if unixfrom:
+            ufrom = msg.get_unixfrom()
+            if not ufrom:
+                ufrom = 'From nobody ' + time.ctime(time.time())
+            print >> self._fp, ufrom
+        self._write(msg)
+
+    #
+    # Protected interface - undocumented ;/
+    #
+
+    def _write(self, msg):
+        # We can't write the headers yet because of the following scenario:
+        # say a multipart message includes the boundary string somewhere in
+        # its body.  We'd have to calculate the new boundary /before/ we write
+        # the headers so that we can write the correct Content-Type:
+        # parameter.
+        #
+        # The way we do this, so as to make the _handle_*() methods simpler,
+        # is to cache any subpart writes into a StringIO.  The we write the
+        # headers and the StringIO contents.  That way, subpart handlers can
+        # Do The Right Thing, and can still modify the Content-Type: header if
+        # necessary.
+        oldfp = self._fp
+        try:
+            self._fp = sfp = StringIO()
+            self._dispatch(msg)
+        finally:
+            self._fp = oldfp
+        # Write the headers.  First we see if the message object wants to
+        # handle that itself.  If not, we'll do it generically.
+        meth = getattr(msg, '_write_headers', None)
+        if meth is None:
+            self._write_headers(msg)
+        else:
+            meth(self)
+        self._fp.write(sfp.getvalue())
+
+    def _dispatch(self, msg):
+        # Get the Content-Type: for the message, then try to dispatch to
+        # self._handle_maintype_subtype().  If there's no handler for the full
+        # MIME type, then dispatch to self._handle_maintype().  If that's
+        # missing too, then dispatch to self._writeBody().
+        ctype = msg.get_type()
+        if ctype is None:
+            # No Content-Type: header so try the default handler
+            self._writeBody(msg)
+        else:
+            # We do have a Content-Type: header.
+            specific = UNDERSCORE.join(ctype.split('/')).replace('-', '_')
+            meth = getattr(self, '_handle_' + specific, None)
+            if meth is None:
+                generic = msg.get_main_type().replace('-', '_')
+                meth = getattr(self, '_handle_' + generic, None)
+                if meth is None:
+                    meth = self._writeBody
+            meth(msg)
+
+    #
+    # Default handlers
+    #
+
+    def _write_headers(self, msg):
+        for h, v in msg.items():
+            # We only write the MIME-Version: header for the outermost
+            # container message.  Unfortunately, we can't use same technique
+            # as for the Unix-From above because we don't know when
+            # MIME-Version: will occur.
+            if h.lower() == 'mime-version' and not self.__first:
+                continue
+            # RFC 2822 says that lines SHOULD be no more than maxheaderlen
+            # characters wide, so we're well within our rights to split long
+            # headers.
+            text = '%s: %s' % (h, v)
+            if self.__maxheaderlen > 0 and len(text) > self.__maxheaderlen:
+                text = self._split_header(text)
+            print >> self._fp, text
+        # A blank line always separates headers from body
+        print >> self._fp
+
+    def _split_header(self, text):
+        maxheaderlen = self.__maxheaderlen
+        # Find out whether any lines in the header are really longer than
+        # maxheaderlen characters wide.  There could be continuation lines
+        # that actually shorten it.  Also, replace hard tabs with 8 spaces.
+        lines = [s.replace('\t', SPACE8) for s in text.split('\n')]
+        for line in lines:
+            if len(line) > maxheaderlen:
+                break
+        else:
+            # No line was actually longer than maxheaderlen characters, so
+            # just return the original unchanged.
+            return text
+        rtn = []
+        for line in text.split('\n'):
+            # Short lines can remain unchanged
+            if len(line.replace('\t', SPACE8)) <= maxheaderlen:
+                rtn.append(line)
+            else:
+                # Try to break the line on semicolons, but if that doesn't
+                # work, then just leave it alone.
+                while len(text) > maxheaderlen:
+                    i = text.rfind(';', 0, maxheaderlen)
+                    if i < 0:
+                        rtn.append(text)
+                        break
+                    rtn.append(text[:i])
+                    text = text[i+1:].lstrip()
+                rtn.append(text)
+        return SEMINLTAB.join(rtn)
+
+    #
+    # Handlers for writing types and subtypes
+    #
+
+    def _handle_text(self, msg):
+        payload = msg.get_payload()
+        if not isinstance(payload, StringType):
+            raise TypeError, 'string payload expected'
+        if self._mangle_from_:
+            payload = fcre.sub('>From ', payload)
+        self._fp.write(payload)
+
+    # Default body handler
+    _writeBody = _handle_text
+
+    def _handle_multipart(self, msg, isdigest=0):
+        # The trick here is to write out each part separately, merge them all
+        # together, and then make sure that the boundary we've chosen isn't
+        # present in the payload.
+        msgtexts = []
+        for part in msg.get_payload():
+            s = StringIO()
+            g = self.__class__(s)
+            g(part, unixfrom=0)
+            msgtexts.append(s.getvalue())
+        # Now make sure the boundary we've selected doesn't appear in any of
+        # the message texts.
+        alltext = NL.join(msgtexts)
+        # BAW: What about boundaries that are wrapped in double-quotes?
+        boundary = msg.get_boundary(failobj=_make_boundary(alltext))
+        # If we had to calculate a new boundary because the body text
+        # contained that string, set the new boundary.  We don't do it
+        # unconditionally because, while set_boundary() preserves order, it
+        # doesn't preserve newlines/continuations in headers.  This is no big
+        # deal in practice, but turns out to be inconvenient for the unittest
+        # suite.
+        if msg.get_boundary() <> boundary:
+            msg.set_boundary(boundary)
+        # Write out any preamble
+        if msg.preamble is not None:
+            self._fp.write(msg.preamble)
+        # First boundary is a bit different; it doesn't have a leading extra
+        # newline.
+        print >> self._fp, '--' + boundary
+        if isdigest:
+            print >> self._fp
+        # Join and write the individual parts
+        joiner = '\n--' + boundary + '\n'
+        if isdigest:
+            # multipart/digest types effectively add an extra newline between
+            # the boundary and the body part.
+            joiner += '\n'
+        self._fp.write(joiner.join(msgtexts))
+        print >> self._fp, '\n--' + boundary + '--',
+        # Write out any epilogue
+        if msg.epilogue is not None:
+            self._fp.write(msg.epilogue)
+
+    def _handle_multipart_digest(self, msg):
+        self._handle_multipart(msg, isdigest=1)
+
+    def _handle_message_rfc822(self, msg):
+        s = StringIO()
+        g = self.__class__(s)
+        # A message/rfc822 should contain a scalar payload which is another
+        # Message object.  Extract that object, stringify it, and write that
+        # out.
+        g(msg.get_payload(), unixfrom=0)
+        self._fp.write(s.getvalue())
+
+
+
+class DecodedGenerator(Generator):
+    """Generator a text representation of a message.
+
+    Like the Generator base class, except that non-text parts are substituted
+    with a format string representing the part.
+    """
+    def __init__(self, outfp, mangle_from_=1, maxheaderlen=78, fmt=None):
+        """Like Generator.__init__() except that an additional optional
+        argument is allowed.
+
+        Walks through all subparts of a message.  If the subpart is of main
+        type `text', then it prints the decoded payload of the subpart.
+
+        Otherwise, fmt is a format string that is used instead of the message
+        payload.  fmt is expanded with the following keywords (in
+        %(keyword)s format):
+
+        type       : Full MIME type of the non-text part
+        maintype   : Main MIME type of the non-text part
+        subtype    : Sub-MIME type of the non-text part
+        filename   : Filename of the non-text part
+        description: Description associated with the non-text part
+        encoding   : Content transfer encoding of the non-text part
+
+        The default value for fmt is None, meaning
+
+        [Non-text (%(type)s) part of message omitted, filename %(filename)s]
+        """
+        Generator.__init__(self, outfp, mangle_from_, maxheaderlen)
+        if fmt is None:
+            fmt = ('[Non-text (%(type)s) part of message omitted, '
+                   'filename %(filename)s]')
+        self._fmt = fmt
+
+    def _dispatch(self, msg):
+        for part in msg.walk():
+            if part.get_main_type('text') == 'text':
+                print >> self, part.get_payload(decode=1)
+            else:
+                print >> self, self._fmt % {
+                    'type'       : part.get_type('[no MIME type]'),
+                    'maintype'   : part.get_main_type('[no main MIME type]'),
+                    'subtype'    : part.get_subtype('[no sub-MIME type]'),
+                    'filename'   : part.get_filename('[no filename]'),
+                    'description': part.get('Content-Description',
+                                            '[no description]'),
+                    'encoding'   : part.get('Content-Transfer-Encoding',
+                                            '[no encoding]'),
+                    }
+
+
+
+# Helper
+def _make_boundary(self, text=None):
+    # Craft a random boundary.  If text is given, ensure that the chosen
+    # boundary doesn't appear in the text.
+    boundary = ('=' * 15) + repr(random.random()).split('.')[1] + '=='
+    if text is None:
+        return boundary
+    b = boundary
+    counter = 0
+    while 1:
+        cre = re.compile('^--' + re.escape(b) + '(--)?$', re.MULTILINE)
+        if not cre.search(text):
+            break
+        b = boundary + '.' + str(counter)
+        counter += 1
+    return b
diff --git a/Lib/email/Image.py b/Lib/email/Image.py
new file mode 100644
index 0000000..d350785
--- /dev/null
+++ b/Lib/email/Image.py
@@ -0,0 +1,46 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Class representing image/* type MIME documents.
+"""
+
+import imghdr
+
+# Intrapackage imports
+import MIMEBase
+import Errors
+import Encoders
+
+
+
+class Image(MIMEBase.MIMEBase):
+    """Class for generating image/* type MIME documents."""
+
+    def __init__(self, _imagedata, _minor=None,
+                 _encoder=Encoders.encode_base64, **_params):
+        """Create an image/* type MIME document.
+
+        _imagedata is a string containing the raw image data.  If this data
+        can be decoded by the standard Python `imghdr' module, then the
+        subtype will be automatically included in the Content-Type: header.
+        Otherwise, you can specify the specific image subtype via the _minor
+        parameter.
+
+        _encoder is a function which will perform the actual encoding for
+        transport of the image data.  It takes one argument, which is this
+        Image instance.  It should use get_payload() and set_payload() to
+        change the payload to the encoded form.  It should also add any
+        Content-Transfer-Encoding: or other headers to the message as
+        necessary.  The default encoding is Base64.
+
+        Any additional keyword arguments are passed to the base class
+        constructor, which turns them into parameters on the Content-Type:
+        header.
+        """
+        if _minor is None:
+            _minor = imghdr.what(None, _imagedata)
+        if _minor is None:
+            raise TypeError, 'Could not guess image _minor type'
+        MIMEBase.MIMEBase.__init__(self, 'image', _minor, **_params)
+        self.set_payload(_imagedata)
+        _encoder(self)
diff --git a/Lib/email/Iterators.py b/Lib/email/Iterators.py
new file mode 100644
index 0000000..998530f
--- /dev/null
+++ b/Lib/email/Iterators.py
@@ -0,0 +1,33 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Various types of useful iterators and generators.
+"""
+
+from __future__ import generators
+from cStringIO import StringIO
+from types import StringType
+
+
+
+def body_line_iterator(msg):
+    """Iterator over the parts, returning the lines in a string payload."""
+    for subpart in msg.walk():
+        payload = subpart.get_payload()
+        if type(payload) is StringType:
+            for line in StringIO(payload):
+                yield line
+
+
+
+def typed_subpart_iterator(msg, major='text', minor=None):
+    """Iterator over the subparts with a given MIME type.
+
+    Use `major' as the main MIME type to match against; this defaults to
+    "text".  Optional `minor' is the MIME subtype to match against; if
+    omitted, only the main type is matched.
+    """
+    for subpart in msg.walk():
+        if subpart.get_main_type() == major:
+            if minor is None or subpart.get_subtype() == minor:
+                yield subpart
diff --git a/Lib/email/MIMEBase.py b/Lib/email/MIMEBase.py
new file mode 100644
index 0000000..e6dda56
--- /dev/null
+++ b/Lib/email/MIMEBase.py
@@ -0,0 +1,24 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Base class for MIME specializations.
+"""
+
+import Message
+
+
+
+class MIMEBase(Message.Message):
+    """Base class for MIME specializations."""
+
+    def __init__(self, _major, _minor, **_params):
+        """This constructor adds a Content-Type: and a MIME-Version: header.
+
+        The Content-Type: header is taken from the _major and _minor
+        arguments.  Additional parameters for this header are taken from the
+        keyword arguments.
+        """
+        Message.Message.__init__(self)
+        ctype = '%s/%s' % (_major, _minor)
+        self.add_header('Content-Type', ctype, **_params)
+        self['MIME-Version'] = '1.0'
diff --git a/Lib/email/Message.py b/Lib/email/Message.py
new file mode 100644
index 0000000..35e2dc5
--- /dev/null
+++ b/Lib/email/Message.py
@@ -0,0 +1,422 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Basic message object for the email package object model.
+"""
+
+from __future__ import generators
+
+import re
+import base64
+import quopri
+from cStringIO import StringIO
+from types import ListType
+
+SEMISPACE = '; '
+
+# Intrapackage imports
+import Errors
+import Utils
+
+
+
+class Message:
+    """Basic message object for use inside the object tree.
+
+    A message object is defined as something that has a bunch of RFC 2822
+    headers and a payload.  If the body of the message is a multipart, then
+    the payload is a list of Messages, otherwise it is a string.
+
+    These objects implement part of the `mapping' interface, which assumes
+    there is exactly one occurrance of the header per message.  Some headers
+    do in fact appear multiple times (e.g. Received:) and for those headers,
+    you must use the explicit API to set or get all the headers.  Not all of
+    the mapping methods are implemented.
+
+    """
+    def __init__(self):
+        self._headers = []
+        self._unixfrom = None
+        self._payload = None
+        # Defaults for multipart messages
+        self.preamble = self.epilogue = None
+
+    def __str__(self):
+        """Return the entire formatted message as a string.
+        This includes the headers, body, and `unixfrom' line.
+        """
+        return self.as_string(unixfrom=1)
+
+    def as_string(self, unixfrom=0):
+        """Return the entire formatted message as a string.
+        Optional `unixfrom' when true, means include the Unix From_ envelope
+        header.
+        """
+        from Generator import Generator
+        fp = StringIO()
+        g = Generator(fp)
+        g(self, unixfrom=unixfrom)
+        return fp.getvalue()
+
+    def is_multipart(self):
+        """Return true if the message consists of multiple parts."""
+        if type(self._payload) is ListType:
+            return 1
+        return 0
+
+    #
+    # Unix From_ line
+    #
+    def set_unixfrom(self, unixfrom):
+        self._unixfrom = unixfrom
+
+    def get_unixfrom(self):
+        return self._unixfrom
+
+    #
+    # Payload manipulation.
+    #
+    def add_payload(self, payload):
+        """Add the given payload to the current payload.
+
+        If the current payload is empty, then the current payload will be made
+        a scalar, set to the given value.
+        """
+        if self._payload is None:
+            self._payload = payload
+        elif type(self._payload) is ListType:
+            self._payload.append(payload)
+        elif self.get_main_type() not in (None, 'multipart'):
+            raise Errors.MultipartConversionError(
+                'Message main Content-Type: must be "multipart" or missing')
+        else:
+            self._payload = [self._payload, payload]
+
+    # A useful synonym
+    attach = add_payload
+
+    def get_payload(self, i=None, decode=0):
+        """Return the current payload exactly as is.
+
+        Optional i returns that index into the payload.
+
+        Optional decode is a flag indicating whether the payload should be
+        decoded or not, according to the Content-Transfer-Encoding: header.
+        When true and the message is not a multipart, the payload will be
+        decoded if this header's value is `quoted-printable' or `base64'.  If
+        some other encoding is used, or the header is missing, the payload is
+        returned as-is (undecoded).  If the message is a multipart and the
+        decode flag is true, then None is returned.
+        """
+        if i is None:
+            payload = self._payload
+        elif type(self._payload) is not ListType:
+            raise TypeError, i
+        else:
+            payload = self._payload[i]
+        if decode:
+            if self.is_multipart():
+                return None
+            cte = self.get('content-transfer-encoding', '')
+            if cte.lower() == 'quoted-printable':
+                return Utils._qdecode(payload)
+            elif cte.lower() == 'base64':
+                return Utils._bdecode(payload)
+        # Everything else, including encodings with 8bit or 7bit are returned
+        # unchanged.
+        return payload
+
+
+    def set_payload(self, payload):
+        """Set the payload to the given value."""
+        self._payload = payload
+
+    #
+    # MAPPING INTERFACE (partial)
+    #
+    def __len__(self):
+        """Get the total number of headers, including duplicates."""
+        return len(self._headers)
+
+    def __getitem__(self, name):
+        """Get a header value.
+
+        Return None if the header is missing instead of raising an exception.
+
+        Note that if the header appeared multiple times, exactly which
+        occurrance gets returned is undefined.  Use getall() to get all
+        the values matching a header field name.
+        """
+        return self.get(name)
+
+    def __setitem__(self, name, val):
+        """Set the value of a header.
+
+        Note: this does not overwrite an existing header with the same field
+        name.  Use __delitem__() first to delete any existing headers.
+        """
+        self._headers.append((name, val))
+
+    def __delitem__(self, name):
+        """Delete all occurrences of a header, if present.
+
+        Does not raise an exception if the header is missing.
+        """
+        name = name.lower()
+        newheaders = []
+        for k, v in self._headers:
+            if k.lower() <> name:
+                newheaders.append((k, v))
+        self._headers = newheaders
+
+    def __contains__(self, key):
+        return key.lower() in [k.lower() for k, v in self._headers]
+
+    def has_key(self, name):
+        """Return true if the message contains the header."""
+        return self[name] <> None
+
+    def keys(self):
+        """Return a list of all the message's header field names.
+
+        These will be sorted in the order they appeared in the original
+        message, and may contain duplicates.  Any fields deleted and
+        re-inserted are always appended to the header list.
+        """
+        return [k for k, v in self._headers]
+
+    def values(self):
+        """Return a list of all the message's header values.
+
+        These will be sorted in the order they appeared in the original
+        message, and may contain duplicates.  Any fields deleted and
+        re-inserted are alwyas appended to the header list.
+        """
+        return [v for k, v in self._headers]
+
+    def items(self):
+        """Get all the message's header fields and values.
+
+        These will be sorted in the order they appeared in the original
+        message, and may contain duplicates.  Any fields deleted and
+        re-inserted are alwyas appended to the header list.
+        """
+        return self._headers[:]
+
+    def get(self, name, failobj=None):
+        """Get a header value.
+
+        Like __getitem__() but return failobj instead of None when the field
+        is missing.
+        """
+        name = name.lower()
+        for k, v in self._headers:
+            if k.lower() == name:
+                return v
+        return failobj
+
+    #
+    # Additional useful stuff
+    #
+
+    def get_all(self, name, failobj=None):
+        """Return a list of all the values for the named field.
+
+        These will be sorted in the order they appeared in the original
+        message, and may contain duplicates.  Any fields deleted and
+        re-inserted are alwyas appended to the header list.
+        """
+        values = []
+        name = name.lower()
+        for k, v in self._headers:
+            if k.lower() == name:
+                values.append(v)
+        return values
+
+    def add_header(self, _name, _value, **_params):
+        """Extended header setting.
+
+        name is the header field to add.  keyword arguments can be used to set
+        additional parameters for the header field, with underscores converted
+        to dashes.  Normally the parameter will be added as key="value" unless
+        value is None, in which case only the key will be added.
+
+        Example:
+
+        msg.add_header('content-disposition', 'attachment', filename='bud.gif')
+
+        """
+        parts = []
+        for k, v in _params.items():
+            if v is None:
+                parts.append(k.replace('_', '-'))
+            else:
+                parts.append('%s="%s"' % (k.replace('_', '-'), v))
+        if _value is not None:
+            parts.insert(0, _value)
+        self._headers.append((_name, SEMISPACE.join(parts)))
+
+    def get_type(self, failobj=None):
+        """Returns the message's content type.
+
+        The returned string is coerced to lowercase and returned as a single
+        string of the form `maintype/subtype'.  If there was no Content-Type:
+        header in the message, failobj is returned (defaults to None).
+        """
+        missing = []
+        value = self.get('content-type', missing)
+        if value is missing:
+            return failobj
+        return re.split(r';\s+', value)[0].lower()
+
+    def get_main_type(self, failobj=None):
+        """Return the message's main content type if present."""
+        missing = []
+        ctype = self.get_type(missing)
+        if ctype is missing:
+            return failobj
+        parts = ctype.split('/')
+        if len(parts) > 0:
+            return ctype.split('/')[0]
+        return failobj
+
+    def get_subtype(self, failobj=None):
+        """Return the message's content subtype if present."""
+        missing = []
+        ctype = self.get_type(missing)
+        if ctype is missing:
+            return failobj
+        parts = ctype.split('/')
+        if len(parts) > 1:
+            return ctype.split('/')[1]
+        return failobj
+
+    def get_params(self, failobj=None, header='content-type'):
+        """Return the message's Content-Type: parameters, as a list.
+
+        Optional failobj is the object to return if there is no Content-Type:
+        header.  Optional header is the header to search instead of
+        Content-Type:
+        """
+        missing = []
+        value = self.get(header, missing)
+        if value is missing:
+            return failobj
+        return re.split(r';\s+', value)[1:]
+
+    def get_param(self, param, failobj=None, header='content-type'):
+        """Return the parameter value if found in the Content-Type: header.
+
+        Optional failobj is the object to return if there is no Content-Type:
+        header.  Optional header is the header to search instead of
+        Content-Type:
+        """
+        param = param.lower()
+        missing = []
+        params = self.get_params(missing, header=header)
+        if params is missing:
+            return failobj
+        for p in params:
+            try:
+                name, val = p.split('=', 1)
+            except ValueError:
+                # Must have been a bare attribute
+                name = p
+                val = ''
+            if name.lower() == param:
+                return Utils.unquote(val)
+        return failobj
+
+    def get_filename(self, failobj=None):
+        """Return the filename associated with the payload if present.
+
+        The filename is extracted from the Content-Disposition: header's
+        `filename' parameter, and it is unquoted.
+        """
+        missing = []
+        filename = self.get_param('filename', missing, 'content-disposition')
+        if filename is missing:
+            return failobj
+        return Utils.unquote(filename.strip())
+
+    def get_boundary(self, failobj=None):
+        """Return the boundary associated with the payload if present.
+
+        The boundary is extracted from the Content-Type: header's `boundary'
+        parameter, and it is unquoted.
+        """
+        missing = []
+        boundary = self.get_param('boundary', missing)
+        if boundary is missing:
+            return failobj
+        return Utils.unquote(boundary.strip())
+
+    def set_boundary(self, boundary):
+        """Set the boundary parameter in Content-Type: to 'boundary'.
+
+        This is subtly different than deleting the Content-Type: header and
+        adding a new one with a new boundary parameter via add_header().  The
+        main difference is that using the set_boundary() method preserves the
+        order of the Content-Type: header in the original message.
+
+        HeaderParseError is raised if the message has no Content-Type: header.
+        """
+        params = self.get_params()
+        if not params:
+            # There was no Content-Type: header, and we don't know what type
+            # to set it to, so raise an exception.
+            raise Errors.HeaderParseError, 'No Content-Type: header found'
+        newparams = []
+        foundp = 0
+        for p in params:
+            if p.lower().startswith('boundary='):
+                newparams.append('boundary="%s"' % boundary)
+                foundp = 1
+            else:
+                newparams.append(p)
+        if not foundp:
+            # The original Content-Type: header had no boundary attribute.
+            # Tack one one the end.  BAW: should we raise an exception
+            # instead???
+            newparams.append('boundary="%s"' % boundary)
+        # Replace the existing Content-Type: header with the new value
+        newheaders = []
+        for h, v in self._headers:
+            if h.lower() == 'content-type':
+                value = v.split(';', 1)[0]
+                newparams.insert(0, value)
+                newheaders.append((h, SEMISPACE.join(newparams)))
+            else:
+                newheaders.append((h, v))
+        self._headers = newheaders
+
+    def walk(self):
+        """Walk over the message tree, yielding each subpart.
+
+        The walk is performed in breadth-first order.  This method is a
+        generator.
+        """
+        if self.is_multipart():
+            for subpart in self.get_payload():
+                for subsubpart in subpart.walk():
+                    yield subsubpart
+        else:
+            yield self
+
+    def get_charsets(self, failobj=None):
+        """Return a list containing the charset(s) used in this message.
+    
+        The returned list of items describes the Content-Type: headers'
+        charset parameter for this message and all the subparts in its
+        payload.
+
+        Each item will either be a string (the value of the charset parameter
+        in the Content-Type: header of that part) or the value of the
+        'failobj' parameter (defaults to None), if the part does not have a
+        main MIME type of "text", or the charset is not defined.
+
+        The list will contain one string for each part of the message, plus
+        one for the container message (i.e. self), so that a non-multipart
+        message will still return a list of length 1.
+        """
+        return [part.get_param('charset', failobj) for part in self.walk()]
diff --git a/Lib/email/MessageRFC822.py b/Lib/email/MessageRFC822.py
new file mode 100644
index 0000000..81cc4dc
--- /dev/null
+++ b/Lib/email/MessageRFC822.py
@@ -0,0 +1,24 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Class for generating message/rfc822 MIME documents.
+"""
+
+import Message
+import MIMEBase
+
+
+
+class MessageRFC822(MIMEBase.MIMEBase):
+    """Class for generating message/rfc822 MIME documents."""
+
+    def __init__(self, _msg):
+        """Create a message/rfc822 type MIME document.
+
+        _msg is a message object and must be an instance of Message, or a
+        derived class of Message, otherwise a TypeError is raised.
+        """
+        MIMEBase.MIMEBase.__init__(self, 'message', 'rfc822')
+        if not isinstance(_msg, Message.Message):
+            raise TypeError, 'Argument is not an instance of Message'
+        self.set_payload(_msg)
diff --git a/Lib/email/Parser.py b/Lib/email/Parser.py
new file mode 100644
index 0000000..cc23d19
--- /dev/null
+++ b/Lib/email/Parser.py
@@ -0,0 +1,154 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""A parser of RFC 2822 and MIME email messages.
+"""
+
+import re
+from cStringIO import StringIO
+
+# Intrapackage imports
+import Errors
+import Message
+
+bcre = re.compile('boundary="?([^"]+)"?', re.IGNORECASE)
+EMPTYSTRING = ''
+NL = '\n'
+
+
+
+class Parser:
+    def __init__(self, _class=Message.Message):
+        """Parser of RFC 2822 and MIME email messages.
+
+        Creates an in-memory object tree representing the email message, which
+        can then be manipulated and turned over to a Generator to return the
+        textual representation of the message.
+
+        The string must be formatted as a block of RFC 2822 headers and header
+        continuation lines, optionally preceeded by a `Unix-from' header.  The
+        header block is terminated either by the end of the string or by a
+        blank line.
+
+        _class is the class to instantiate for new message objects when they
+        must be created.  This class must have a constructor that can take
+        zero arguments.  Default is Message.Message.
+        """
+        self._class = _class
+
+    def parse(self, fp):
+        root = self._class()
+        self._parseheaders(root, fp)
+        self._parsebody(root, fp)
+        return root
+
+    def parsestr(self, text):
+        return self.parse(StringIO(text))
+
+    def _parseheaders(self, container, fp):
+        # Parse the headers, returning a list of header/value pairs.  None as
+        # the header means the Unix-From header.
+        lastheader = ''
+        lastvalue = []
+        lineno = 0
+        while 1:
+            line = fp.readline()[:-1]
+            if not line or not line.strip():
+                break
+            lineno += 1
+            # Check for initial Unix From_ line
+            if line.startswith('From '):
+                if lineno == 1:
+                    container.set_unixfrom(line)
+                    continue
+                else:
+                    raise Errors.HeaderParseError(
+                        'Unix-from in headers after first rfc822 header')
+            #
+            # Header continuation line
+            if line[0] in ' \t':
+                if not lastheader:
+                    raise Errors.HeaderParseError(
+                        'Continuation line seen before first header')
+                lastvalue.append(line)
+                continue
+            # Normal, non-continuation header.  BAW: this should check to make
+            # sure it's a legal header, e.g. doesn't contain spaces.  Also, we
+            # should expose the header matching algorithm in the API, and
+            # allow for a non-strict parsing mode (that ignores the line
+            # instead of raising the exception).
+            i = line.find(':')
+            if i < 0:
+                raise Errors.HeaderParseError(
+                    'Not a header, not a continuation')
+            if lastheader:
+                container[lastheader] = NL.join(lastvalue)
+            lastheader = line[:i]
+            lastvalue = [line[i+1:].lstrip()]
+        # Make sure we retain the last header
+        if lastheader:
+            container[lastheader] = NL.join(lastvalue)
+
+    def _parsebody(self, container, fp):
+        # Parse the body, but first split the payload on the content-type
+        # boundary if present.
+        boundary = isdigest = None
+        ctype = container['content-type']
+        if ctype:
+            mo = bcre.search(ctype)
+            if mo:
+                boundary = mo.group(1)
+            isdigest = container.get_type() == 'multipart/digest'
+        # If there's a boundary, split the payload text into its constituent
+        # parts and parse each separately.  Otherwise, just parse the rest of
+        # the body as a single message.  Note: any exceptions raised in the
+        # recursive parse need to have their line numbers coerced.
+        if boundary:
+            preamble = epilogue = None
+            # Split into subparts.  The first boundary we're looking for won't
+            # have the leading newline since we're at the start of the body
+            # text.
+            separator = '--' + boundary
+            payload = fp.read()
+            start = payload.find(separator)
+            if start < 0:
+                raise Errors.BoundaryError(
+                    "Couldn't find starting boundary: %s" % boundary)
+            if start > 0:
+                # there's some pre-MIME boundary preamble
+                preamble = payload[0:start]
+            start += len(separator) + 1 + isdigest
+            terminator = payload.find('\n' + separator + '--', start)
+            if terminator < 0:
+                raise Errors.BoundaryError(
+                    "Couldn't find terminating boundary: %s" % boundary)
+            if terminator+len(separator)+3 < len(payload):
+                # there's some post-MIME boundary epilogue
+                epilogue = payload[terminator+len(separator)+3:]
+            # We split the textual payload on the boundary separator, which
+            # includes the trailing newline.  If the container is a
+            # multipart/digest then the subparts are by default message/rfc822
+            # instead of text/plain.  In that case, they'll have an extra
+            # newline before the headers to distinguish the message's headers
+            # from the subpart headers.
+            if isdigest:
+                separator += '\n\n'
+            else:
+                separator += '\n'
+            parts = payload[start:terminator].split('\n' + separator)
+            for part in parts:
+                msgobj = self.parsestr(part)
+                container.preamble = preamble
+                container.epilogue = epilogue
+                container.add_payload(msgobj)
+        elif ctype == 'message/rfc822':
+            # Create a container for the payload, but watch out for there not
+            # being any headers left
+            try:
+                msg = self.parse(fp)
+            except Errors.HeaderParseError:
+                msg = self._class()
+                self._parsebody(msg, fp)
+            container.add_payload(msg)
+        else:
+            container.add_payload(fp.read())
diff --git a/Lib/email/Text.py b/Lib/email/Text.py
new file mode 100644
index 0000000..5abfd0b
--- /dev/null
+++ b/Lib/email/Text.py
@@ -0,0 +1,41 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Class representing text/* type MIME documents.
+"""
+
+import MIMEBase
+from Encoders import encode_7or8bit
+
+
+
+class Text(MIMEBase.MIMEBase):
+    """Class for generating text/* type MIME documents."""
+
+    def __init__(self, _text, _minor='plain', _charset='us-ascii',
+                 _encoder=encode_7or8bit):
+        """Create a text/* type MIME document.
+
+        _text is the string for this message object.  If the text does not end
+        in a newline, one is added.
+
+        _minor is the minor content type, defaulting to "plain".
+
+        _charset is the character set parameter added to the Content-Type:
+        header.  This defaults to "us-ascii".
+
+        _encoder is a function which will perform the actual encoding for
+        transport of the text data.  It takes one argument, which is this
+        Text instance.  It should use get_payload() and set_payload() to
+        change the payload to the encoded form.  It should also add any
+        Content-Transfer-Encoding: or other headers to the message as
+        necessary.  The default encoding doesn't actually modify the payload,
+        but it does set Content-Transfer-Encoding: to either `7bit' or `8bit'
+        as appropriate.
+        """
+        MIMEBase.MIMEBase.__init__(self, 'text', _minor,
+                                   **{'charset': _charset})
+        if _text and _text[-1] <> '\n':
+            _text += '\n'
+        self.set_payload(_text)
+        _encoder(self)
diff --git a/Lib/email/Utils.py b/Lib/email/Utils.py
new file mode 100644
index 0000000..6bbf2d3
--- /dev/null
+++ b/Lib/email/Utils.py
@@ -0,0 +1,104 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""Miscellaneous utilities.
+"""
+
+import re
+
+from rfc822 import unquote, quote, parseaddr
+from rfc822 import dump_address_pair
+from rfc822 import AddrlistClass as _AddrlistClass
+from rfc822 import parsedate_tz, parsedate, mktime_tz, formatdate
+
+from quopri import decodestring as _qdecode
+import base64
+
+# Intrapackage imports
+from Encoders import _bencode, _qencode
+
+COMMASPACE = ', '
+UEMPTYSTRING = u''
+
+
+
+# Helpers
+
+def _identity(s):
+    return s
+
+
+def _bdecode(s):
+    if not s:
+        return s
+    # We can't quite use base64.encodestring() since it tacks on a "courtesy
+    # newline".  Blech!
+    if not s:
+        return s
+    hasnewline = (s[-1] == '\n')
+    value = base64.decodestring(s)
+    if not hasnewline and value[-1] == '\n':
+        return value[:-1]
+    return value
+
+
+
+def getaddresses(fieldvalues):
+    """Return a list of (REALNAME, EMAIL) for each fieldvalue."""
+    all = COMMASPACE.join(fieldvalues)
+    a = _AddrlistClass(all)
+    return a.getaddrlist()
+
+
+
+ecre = re.compile(r'''
+  =\?                   # literal =?
+  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
+  \?                    # literal ?
+  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
+  \?                    # literal ?
+  (?P<atom>.*?)         # non-greedy up to the next ?= is the atom
+  \?=                   # literal ?=
+  ''', re.VERBOSE | re.IGNORECASE)
+
+
+def decode(s):
+    """Return a decoded string according to RFC 2047, as a unicode string."""
+    rtn = []
+    parts = ecre.split(s, 1)
+    while parts:
+        # If there are less than 4 parts, it can't be encoded and we're done
+        if len(parts) < 5:
+            rtn.extend(parts)
+            break
+        # The first element is any non-encoded leading text
+        rtn.append(parts[0])
+        charset = parts[1]
+        encoding = parts[2]
+        atom = parts[3]
+        # The next chunk to decode should be in parts[4]
+        parts = ecre.split(parts[4])
+        # The encoding must be either `q' or `b', case-insensitive
+        if encoding.lower() == 'q':
+            func = _qdecode
+        elif encoding.lower() == 'b':
+            func = _bdecode
+        else:
+            func = _identity
+        # Decode and get the unicode in the charset
+        rtn.append(unicode(func(atom), charset))
+    # Now that we've decoded everything, we just need to join all the parts
+    # together into the final string.
+    return UEMPTYSTRING.join(rtn)
+
+
+
+def encode(s, charset='iso-8859-1', encoding='q'):
+    """Encode a string according to RFC 2047."""
+    if encoding.lower() == 'q':
+        estr = _qencode(s)
+    elif encoding.lower() == 'b':
+        estr = _bencode(s)
+    else:
+        raise ValueError, 'Illegal encoding code: ' + encoding
+    return '=?%s?%s?%s?=' % (charset.lower(), encoding.lower(), estr)
diff --git a/Lib/email/__init__.py b/Lib/email/__init__.py
new file mode 100644
index 0000000..4995114
--- /dev/null
+++ b/Lib/email/__init__.py
@@ -0,0 +1,34 @@
+# Copyright (C) 2001 Python Software Foundation
+# Author: barry@zope.com (Barry Warsaw)
+
+"""A package for parsing, handling, and generating email messages.
+"""
+
+__version__ = '1.0'
+
+__all__ = ['Encoders',
+           'Errors',
+           'Generator',
+           'Image',
+           'Iterators',
+           'MIMEBase',
+           'Message',
+           'MessageRFC822',
+           'Parser',
+           'Text',
+           'Utils',
+           'message_from_string',
+           'message_from_file',
+           ]
+
+
+
+# Some convenience routines
+from Parser import Parser as _Parser
+from Message import Message as _Message
+
+def message_from_string(s, _class=_Message):
+    return _Parser(_class).parsestr(s)
+
+def message_from_file(fp, _class=_Message):
+    return _Parser(_class).parse(fp)