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author | Guido van Rossum <guido@python.org> | 2007-08-25 13:43:02 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 2007-08-25 13:43:02 (GMT) |
commit | 6398b7a351d04408fa8ce0204d78559e8d6ac98f (patch) | |
tree | 5f274983fa91009d1a7b4bfa26de59a83942581f /Lib/email/generator.py | |
parent | f616b224506ef17ac9ab4378c92b99ae816b88f7 (diff) | |
download | cpython-6398b7a351d04408fa8ce0204d78559e8d6ac98f.zip cpython-6398b7a351d04408fa8ce0204d78559e8d6ac98f.tar.gz cpython-6398b7a351d04408fa8ce0204d78559e8d6ac98f.tar.bz2 |
Remove the email package for now.
Once Barry and the email-sig have a working new version
we'll add it back.
If it doesn't make the 3.0a deadline (release August 31), too bad.
Diffstat (limited to 'Lib/email/generator.py')
-rw-r--r-- | Lib/email/generator.py | 354 |
1 files changed, 0 insertions, 354 deletions
diff --git a/Lib/email/generator.py b/Lib/email/generator.py deleted file mode 100644 index fb03c9f..0000000 --- a/Lib/email/generator.py +++ /dev/null @@ -1,354 +0,0 @@ -# Copyright (C) 2001-2006 Python Software Foundation -# Author: Barry Warsaw -# Contact: email-sig@python.org - -"""Classes to generate plain text from a message object tree.""" - -__all__ = ['Generator', 'DecodedGenerator'] - -import re -import sys -import time -import random -import warnings - -from io import StringIO -from email.header import Header - -UNDERSCORE = '_' -NL = '\n' - -fcre = re.compile(r'^From ', re.MULTILINE) - -def _is8bitstring(s): - if isinstance(s, bytes): - try: - str(s, 'us-ascii') - return True - except UnicodeError: - pass - elif isinstance(s, str): - try: - s.decode('us-ascii') - return True - except UnicodeError: - pass - return False - - -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_=True, 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 (the default), 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 split as - defined in the Header class. Set maxheaderlen to zero to disable - header wrapping. The default is 78, as recommended (but not required) - by RFC 2822. - """ - self._fp = outfp - self._mangle_from_ = mangle_from_ - self._maxheaderlen = maxheaderlen - - def write(self, s): - # Just delegate to the file object - self._fp.write(s) - - def flatten(self, msg, unixfrom=False): - """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 False 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(ufrom, file=self._fp) - self._write(msg) - - def clone(self, fp): - """Clone this generator with the exact same options.""" - return self.__class__(fp, self._mangle_from_, self._maxheaderlen) - - # - # 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(). - main = msg.get_content_maintype() - sub = msg.get_content_subtype() - specific = UNDERSCORE.join((main, sub)).replace('-', '_') - meth = getattr(self, '_handle_' + specific, None) - if meth is None: - generic = main.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(): - print('%s:' % h, end=' ', file=self._fp) - if self._maxheaderlen == 0: - # Explicit no-wrapping - print(v, file=self._fp) - elif isinstance(v, Header): - # Header instances know what to do - print(v.encode(), file=self._fp) - elif _is8bitstring(v): - # If we have raw 8bit data in a byte string, we have no idea - # what the encoding is. There is no safe way to split this - # string. If it's ascii-subset, then we could do a normal - # ascii split, but if it's multibyte then we could break the - # string. There's no way to know so the least harm seems to - # be to not split the string and risk it being too long. - print(v, file=self._fp) - else: - # Header's got lots of smarts, so use it. - print(Header( - v, maxlinelen=self._maxheaderlen, - header_name=h, continuation_ws='\t').encode(), file=self._fp) - # A blank line always separates headers from body - print(file=self._fp) - - # - # Handlers for writing types and subtypes - # - - def _handle_text(self, msg): - payload = msg.get_payload() - if payload is None: - return - if not isinstance(payload, basestring): - raise TypeError('string payload expected: %s' % type(payload)) - if self._mangle_from_: - payload = fcre.sub('>From ', payload) - self._fp.write(payload) - - # Default body handler - _writeBody = _handle_text - - def _handle_multipart(self, msg): - # 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 = [] - subparts = msg.get_payload() - if subparts is None: - subparts = [] - elif isinstance(subparts, basestring): - # e.g. a non-strict parse of a message with no starting boundary. - self._fp.write(subparts) - return - elif not isinstance(subparts, list): - # Scalar payload - subparts = [subparts] - for part in subparts: - s = StringIO() - g = self.clone(s) - g.flatten(part, unixfrom=False) - 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) - # If there's a preamble, write it out, with a trailing CRLF - if msg.preamble is not None: - print(msg.preamble, file=self._fp) - # dash-boundary transport-padding CRLF - print('--' + boundary, file=self._fp) - # body-part - if msgtexts: - self._fp.write(msgtexts.pop(0)) - # *encapsulation - # --> delimiter transport-padding - # --> CRLF body-part - for body_part in msgtexts: - # delimiter transport-padding CRLF - print('\n--' + boundary, file=self._fp) - # body-part - self._fp.write(body_part) - # close-delimiter transport-padding - self._fp.write('\n--' + boundary + '--') - if msg.epilogue is not None: - print(file=self._fp) - self._fp.write(msg.epilogue) - - def _handle_message_delivery_status(self, msg): - # We can't just write the headers directly to self's file object - # because this will leave an extra newline between the last header - # block and the boundary. Sigh. - blocks = [] - for part in msg.get_payload(): - s = StringIO() - g = self.clone(s) - g.flatten(part, unixfrom=False) - text = s.getvalue() - lines = text.split('\n') - # Strip off the unnecessary trailing empty line - if lines and lines[-1] == '': - blocks.append(NL.join(lines[:-1])) - else: - blocks.append(text) - # Now join all the blocks with an empty line. This has the lovely - # effect of separating each block with an empty line, but not adding - # an extra one after the last one. - self._fp.write(NL.join(blocks)) - - def _handle_message(self, msg): - s = StringIO() - g = self.clone(s) - # The payload of a message/rfc822 part should be a multipart sequence - # of length 1. The zeroth element of the list should be the Message - # object for the subpart. Extract that object, stringify it, and - # write it out. - g.flatten(msg.get_payload(0), unixfrom=False) - self._fp.write(s.getvalue()) - - - -_FMT = '[Non-text (%(type)s) part of message omitted, filename %(filename)s]' - -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_=True, 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: - self._fmt = _FMT - else: - self._fmt = fmt - - def _dispatch(self, msg): - for part in msg.walk(): - maintype = part.get_content_maintype() - if maintype == 'text': - print(part.get_payload(decode=True), file=self) - elif maintype == 'multipart': - # Just skip this - pass - else: - print(self._fmt % { - 'type' : part.get_content_type(), - 'maintype' : part.get_content_maintype(), - 'subtype' : part.get_content_subtype(), - 'filename' : part.get_filename('[no filename]'), - 'description': part.get('Content-Description', - '[no description]'), - 'encoding' : part.get('Content-Transfer-Encoding', - '[no encoding]'), - }, file=self) - - - -# Helper -_width = len(repr(sys.maxint-1)) -_fmt = '%%0%dd' % _width - -def _make_boundary(text=None): - # Craft a random boundary. If text is given, ensure that the chosen - # boundary doesn't appear in the text. - token = random.randrange(sys.maxint) - boundary = ('=' * 15) + (_fmt % token) + '==' - if text is None: - return boundary - b = boundary - counter = 0 - while True: - cre = re.compile('^--' + re.escape(b) + '(--)?$', re.MULTILINE) - if not cre.search(text): - break - b = boundary + '.' + str(counter) - counter += 1 - return b |