in Lib/email/feedparser.py [0:0]
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):
defect = errors.MissingHeaderBodySeparatorDefect()
self.policy.handle_defect(self._cur, defect)
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 raise 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.
defect = errors.NoBoundaryInMultipartDefect()
self.policy.handle_defect(self._cur, defect)
lines = []
for line in self._input:
if line is NeedMoreData:
yield NeedMoreData
continue
lines.append(line)
self._cur.set_payload(EMPTYSTRING.join(lines))
return
# Make sure a valid content type was specified per RFC 2045:6.4.
if (str(self._cur.get('content-transfer-encoding', '8bit')).lower()
not in ('7bit', '8bit', 'binary')):
defect = errors.InvalidMultipartContentTransferEncodingDefect()
self.policy.handle_defect(self._cur, defect)
# 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
close_boundary_seen = 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'):
close_boundary_seen = True
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._payload
if isinstance(payload, str):
mo = NLCRE_eol.search(payload)
if mo:
payload = payload[:-len(mo.group(0))]
self._last._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.
if capturing_preamble:
defect = errors.StartBoundaryNotFoundDefect()
self.policy.handle_defect(self._cur, defect)
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 we're not processing the preamble, then we might have seen
# EOF without seeing that end boundary...that is also a defect.
if not close_boundary_seen:
defect = errors.CloseBoundaryNotFoundDefect()
self.policy.handle_defect(self._cur, defect)
return
# Everything from here to the EOF is epilogue. 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))