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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/feedparser.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/feedparser.py')
-rw-r--r-- | Lib/email/feedparser.py | 480 |
1 files changed, 0 insertions, 480 deletions
diff --git a/Lib/email/feedparser.py b/Lib/email/feedparser.py deleted file mode 100644 index 9ed8e4d..0000000 --- a/Lib/email/feedparser.py +++ /dev/null @@ -1,480 +0,0 @@ -# Copyright (C) 2004-2006 Python Software Foundation -# Authors: Baxter, Wouters and Warsaw -# Contact: email-sig@python.org - -"""FeedParser - An email feed parser. - -The feed parser implements an interface for incrementally parsing an email -message, line by line. This has advantages for certain applications, such as -those reading email messages off a socket. - -FeedParser.feed() is the primary interface for pushing new data into the -parser. It returns when there's nothing more it can do with the available -data. When you have no more data to push into the parser, call .close(). -This completes the parsing and returns the root message object. - -The other advantage of this parser is that it will never throw a parsing -exception. Instead, when it finds something unexpected, it adds a 'defect' to -the current message. Defects are just instances that live on the message -object's .defects attribute. -""" - -__all__ = ['FeedParser'] - -import re - -from email import errors -from email import message - -NLCRE = re.compile('\r\n|\r|\n') -NLCRE_bol = re.compile('(\r\n|\r|\n)') -NLCRE_eol = re.compile('(\r\n|\r|\n)$') -NLCRE_crack = re.compile('(\r\n|\r|\n)') -# RFC 2822 $3.6.8 Optional fields. ftext is %d33-57 / %d59-126, Any character -# except controls, SP, and ":". -headerRE = re.compile(r'^(From |[\041-\071\073-\176]{1,}:|[\t ])') -EMPTYSTRING = '' -NL = '\n' - -NeedMoreData = object() - - - -class BufferedSubFile(object): - """A file-ish object that can have new data loaded into it. - - You can also push and pop line-matching predicates onto a stack. When the - current predicate matches the current line, a false EOF response - (i.e. empty string) is returned instead. This lets the parser adhere to a - simple abstraction -- it parses until EOF closes the current message. - """ - def __init__(self): - # The last partial line pushed into this object. - self._partial = '' - # The list of full, pushed lines, in reverse order - self._lines = [] - # The stack of false-EOF checking predicates. - self._eofstack = [] - # A flag indicating whether the file has been closed or not. - self._closed = False - - def push_eof_matcher(self, pred): - self._eofstack.append(pred) - - def pop_eof_matcher(self): - return self._eofstack.pop() - - def close(self): - # Don't forget any trailing partial line. - self._lines.append(self._partial) - self._partial = '' - self._closed = True - - def readline(self): - if not self._lines: - if self._closed: - return '' - return NeedMoreData - # Pop the line off the stack and see if it matches the current - # false-EOF predicate. - line = self._lines.pop() - # RFC 2046, section 5.1.2 requires us to recognize outer level - # boundaries at any level of inner nesting. Do this, but be sure it's - # in the order of most to least nested. - for ateof in self._eofstack[::-1]: - if ateof(line): - # We're at the false EOF. But push the last line back first. - self._lines.append(line) - return '' - return line - - def unreadline(self, line): - # Let the consumer push a line back into the buffer. - assert line is not NeedMoreData - self._lines.append(line) - - def push(self, data): - """Push some new data into this object.""" - # Handle any previous leftovers - data, self._partial = self._partial + data, '' - # Crack into lines, but preserve the newlines on the end of each - parts = NLCRE_crack.split(data) - # The *ahem* interesting behaviour of re.split when supplied grouping - # parentheses is that the last element of the resulting list is the - # data after the final RE. In the case of a NL/CR terminated string, - # this is the empty string. - self._partial = parts.pop() - # parts is a list of strings, alternating between the line contents - # and the eol character(s). Gather up a list of lines after - # re-attaching the newlines. - lines = [] - for i in range(len(parts) // 2): - lines.append(parts[i*2] + parts[i*2+1]) - self.pushlines(lines) - - def pushlines(self, lines): - # Reverse and insert at the front of the lines. - self._lines[:0] = lines[::-1] - - def is_closed(self): - return self._closed - - def __iter__(self): - return self - - def __next__(self): - line = self.readline() - if line == '': - raise StopIteration - return line - - - -class FeedParser: - """A feed-style parser of email.""" - - def __init__(self, _factory=message.Message): - """_factory is called with no arguments to create a new message obj""" - self._factory = _factory - self._input = BufferedSubFile() - self._msgstack = [] - self._parse = self._parsegen().__next__ - self._cur = None - self._last = None - self._headersonly = False - - # Non-public interface for supporting Parser's headersonly flag - def _set_headersonly(self): - self._headersonly = True - - def feed(self, data): - """Push more data into the parser.""" - self._input.push(data) - self._call_parse() - - def _call_parse(self): - try: - self._parse() - except StopIteration: - pass - - def close(self): - """Parse all remaining data and return the root message object.""" - self._input.close() - self._call_parse() - root = self._pop_message() - assert not self._msgstack - # Look for final set of defects - if root.get_content_maintype() == 'multipart' \ - and not root.is_multipart(): - root.defects.append(errors.MultipartInvariantViolationDefect()) - return root - - def _new_message(self): - msg = self._factory() - if self._cur and self._cur.get_content_type() == 'multipart/digest': - msg.set_default_type('message/rfc822') - if self._msgstack: - self._msgstack[-1].attach(msg) - self._msgstack.append(msg) - self._cur = msg - self._last = msg - - def _pop_message(self): - retval = self._msgstack.pop() - if self._msgstack: - self._cur = self._msgstack[-1] - else: - self._cur = None - return retval - - def _parsegen(self): - # Create a new message and start by parsing headers. - self._new_message() - headers = [] - # Collect the headers, searching for a line that doesn't match the RFC - # 2822 header or continuation pattern (including an empty line). - for line in self._input: - if line is NeedMoreData: - yield NeedMoreData - continue - if not headerRE.match(line): - # If we saw the RFC defined header/body separator - # (i.e. newline), just throw it away. Otherwise the line is - # part of the body so push it back. - if not NLCRE.match(line): - self._input.unreadline(line) - break - headers.append(line) - # Done with the headers, so parse them and figure out what we're - # supposed to see in the body of the message. - self._parse_headers(headers) - # Headers-only parsing is a backwards compatibility hack, which was - # necessary in the older parser, which could throw errors. All - # remaining lines in the input are thrown into the message body. - if self._headersonly: - lines = [] - while True: - line = self._input.readline() - if line is NeedMoreData: - yield NeedMoreData - continue - if line == '': - break - lines.append(line) - self._cur.set_payload(EMPTYSTRING.join(lines)) - return - if self._cur.get_content_type() == 'message/delivery-status': - # message/delivery-status contains blocks of headers separated by - # a blank line. We'll represent each header block as a separate - # nested message object, but the processing is a bit different - # than standard message/* types because there is no body for the - # nested messages. A blank line separates the subparts. - while True: - self._input.push_eof_matcher(NLCRE.match) - for retval in self._parsegen(): - if retval is NeedMoreData: - yield NeedMoreData - continue - break - msg = self._pop_message() - # We need to pop the EOF matcher in order to tell if we're at - # the end of the current file, not the end of the last block - # of message headers. - self._input.pop_eof_matcher() - # The input stream must be sitting at the newline or at the - # EOF. We want to see if we're at the end of this subpart, so - # first consume the blank line, then test the next line to see - # if we're at this subpart's EOF. - while True: - line = self._input.readline() - if line is NeedMoreData: - yield NeedMoreData - continue - break - while True: - line = self._input.readline() - if line is NeedMoreData: - yield NeedMoreData - continue - break - if line == '': - break - # Not at EOF so this is a line we're going to need. - self._input.unreadline(line) - return - if self._cur.get_content_maintype() == 'message': - # The message claims to be a message/* type, then what follows is - # another RFC 2822 message. - for retval in self._parsegen(): - if retval is NeedMoreData: - yield NeedMoreData - continue - break - self._pop_message() - return - if self._cur.get_content_maintype() == 'multipart': - boundary = self._cur.get_boundary() - if boundary is None: - # The message /claims/ to be a multipart but it has not - # defined a boundary. That's a problem which we'll handle by - # reading everything until the EOF and marking the message as - # defective. - self._cur.defects.append(errors.NoBoundaryInMultipartDefect()) - lines = [] - for line in self._input: - if line is NeedMoreData: - yield NeedMoreData - continue - lines.append(line) - self._cur.set_payload(EMPTYSTRING.join(lines)) - return - # Create a line match predicate which matches the inter-part - # boundary as well as the end-of-multipart boundary. Don't push - # this onto the input stream until we've scanned past the - # preamble. - separator = '--' + boundary - boundaryre = re.compile( - '(?P<sep>' + re.escape(separator) + - r')(?P<end>--)?(?P<ws>[ \t]*)(?P<linesep>\r\n|\r|\n)?$') - capturing_preamble = True - preamble = [] - linesep = False - while True: - line = self._input.readline() - if line is NeedMoreData: - yield NeedMoreData - continue - if line == '': - break - mo = boundaryre.match(line) - if mo: - # If we're looking at the end boundary, we're done with - # this multipart. If there was a newline at the end of - # the closing boundary, then we need to initialize the - # epilogue with the empty string (see below). - if mo.group('end'): - linesep = mo.group('linesep') - break - # We saw an inter-part boundary. Were we in the preamble? - if capturing_preamble: - if preamble: - # According to RFC 2046, the last newline belongs - # to the boundary. - lastline = preamble[-1] - eolmo = NLCRE_eol.search(lastline) - if eolmo: - preamble[-1] = lastline[:-len(eolmo.group(0))] - self._cur.preamble = EMPTYSTRING.join(preamble) - capturing_preamble = False - self._input.unreadline(line) - continue - # We saw a boundary separating two parts. Consume any - # multiple boundary lines that may be following. Our - # interpretation of RFC 2046 BNF grammar does not produce - # body parts within such double boundaries. - while True: - line = self._input.readline() - if line is NeedMoreData: - yield NeedMoreData - continue - mo = boundaryre.match(line) - if not mo: - self._input.unreadline(line) - break - # Recurse to parse this subpart; the input stream points - # at the subpart's first line. - self._input.push_eof_matcher(boundaryre.match) - for retval in self._parsegen(): - if retval is NeedMoreData: - yield NeedMoreData - continue - break - # Because of RFC 2046, the newline preceding the boundary - # separator actually belongs to the boundary, not the - # previous subpart's payload (or epilogue if the previous - # part is a multipart). - if self._last.get_content_maintype() == 'multipart': - epilogue = self._last.epilogue - if epilogue == '': - self._last.epilogue = None - elif epilogue is not None: - mo = NLCRE_eol.search(epilogue) - if mo: - end = len(mo.group(0)) - self._last.epilogue = epilogue[:-end] - else: - payload = self._last.get_payload() - if isinstance(payload, basestring): - mo = NLCRE_eol.search(payload) - if mo: - payload = payload[:-len(mo.group(0))] - self._last.set_payload(payload) - self._input.pop_eof_matcher() - self._pop_message() - # Set the multipart up for newline cleansing, which will - # happen if we're in a nested multipart. - self._last = self._cur - else: - # I think we must be in the preamble - assert capturing_preamble - preamble.append(line) - # We've seen either the EOF or the end boundary. If we're still - # capturing the preamble, we never saw the start boundary. Note - # that as a defect and store the captured text as the payload. - # Everything from here to the EOF is epilogue. - if capturing_preamble: - self._cur.defects.append(errors.StartBoundaryNotFoundDefect()) - self._cur.set_payload(EMPTYSTRING.join(preamble)) - epilogue = [] - for line in self._input: - if line is NeedMoreData: - yield NeedMoreData - continue - self._cur.epilogue = EMPTYSTRING.join(epilogue) - return - # If the end boundary ended in a newline, we'll need to make sure - # the epilogue isn't None - if linesep: - epilogue = [''] - else: - epilogue = [] - for line in self._input: - if line is NeedMoreData: - yield NeedMoreData - continue - epilogue.append(line) - # Any CRLF at the front of the epilogue is not technically part of - # the epilogue. Also, watch out for an empty string epilogue, - # which means a single newline. - if epilogue: - firstline = epilogue[0] - bolmo = NLCRE_bol.match(firstline) - if bolmo: - epilogue[0] = firstline[len(bolmo.group(0)):] - self._cur.epilogue = EMPTYSTRING.join(epilogue) - return - # Otherwise, it's some non-multipart type, so the entire rest of the - # file contents becomes the payload. - lines = [] - for line in self._input: - if line is NeedMoreData: - yield NeedMoreData - continue - lines.append(line) - self._cur.set_payload(EMPTYSTRING.join(lines)) - - def _parse_headers(self, lines): - # Passed a list of lines that make up the headers for the current msg - lastheader = '' - lastvalue = [] - for lineno, line in enumerate(lines): - # Check for continuation - if line[0] in ' \t': - if not lastheader: - # The first line of the headers was a continuation. This - # is illegal, so let's note the defect, store the illegal - # line, and ignore it for purposes of headers. - defect = errors.FirstHeaderLineIsContinuationDefect(line) - self._cur.defects.append(defect) - continue - lastvalue.append(line) - continue - if lastheader: - # XXX reconsider the joining of folded lines - lhdr = EMPTYSTRING.join(lastvalue)[:-1].rstrip('\r\n') - self._cur[lastheader] = lhdr - lastheader, lastvalue = '', [] - # Check for envelope header, i.e. unix-from - if line.startswith('From '): - if lineno == 0: - # Strip off the trailing newline - mo = NLCRE_eol.search(line) - if mo: - line = line[:-len(mo.group(0))] - self._cur.set_unixfrom(line) - continue - elif lineno == len(lines) - 1: - # Something looking like a unix-from at the end - it's - # probably the first line of the body, so push back the - # line and stop. - self._input.unreadline(line) - return - else: - # Weirdly placed unix-from line. Note this as a defect - # and ignore it. - defect = errors.MisplacedEnvelopeHeaderDefect(line) - self._cur.defects.append(defect) - continue - # Split the line on the colon separating field name from value. - i = line.find(':') - if i < 0: - defect = errors.MalformedHeaderDefect(line) - self._cur.defects.append(defect) - continue - lastheader = line[:i] - lastvalue = [line[i+1:].lstrip()] - # Done with all the lines, so handle the last header. - if lastheader: - # XXX reconsider the joining of folded lines - self._cur[lastheader] = EMPTYSTRING.join(lastvalue).rstrip('\r\n') |