Python import email parser code#

Value = re.sub(r'(? email.parser / email. # crude CRLF-FWS-between-encoded-word matching Because in practice, there are email clients out there that use EW in structured headers, regardless. The work-around regex is a bit more complicated, but ideally the EW handling should use a specialist FWS token to delimit encoded-word sections that renders to '' as is done in unstructured headers, but everywhere. Removing the FWS after CRLF is the wrong thing to do, **unless** RFC2047 separating encoded-word tokens. Right, re-educating myself on the MIME RFCs, and found where the same issue is being discussed for previous incarnations of the email library.

Value = re.sub(r'(?> msg = Parser(policy=custom_policy).parse(StringIO(msgdata)) # remove any leading whitespace from header lines

Since unstructured header parsing doesn't mind if a space is missing between encoded-word atoms, the work-around is to explicitly remove the space at the start of every line this can be done in a custom policy:Д¬lass UnfoldingHeaderEmailPolicy(EmailPolicy):Дef header_fetch_parse(self, name, value): from email.parser import Parser The email.parser is the library we want.

Python import email parser code#

I searched around till I found a good library to open emails in Python, and this reduced the code from hundreds to tens of lines. I even wrote some code for it, but it was hundreds of lines long. But for the From header, AddressHeader parser does not, the space at the start of the line is retained, and the surrogate escapes at the end of one encoded-word and the start start of the next encoded-word never ajoin, so the later handling of turning surrogates back into proper data fails. Originally, I was going to parse the file by hand (using regexes). Subject '=?utf-8?b?c8qHdcSxb2THnXBvyZQgOC3ihLLiiqXiiKkgx53Kh8qOcS3E?= =?utf-8?b?scqHyoNuya8gyaXKh8Sxyo0gx53Gg8mQc3PHncmvIMqHc8edyocgybnHncaDdW/Kgw=?='ДЇor the Subject header, _header_value_parser.get_unstructured is used, which *expects* there to be spaces between encoded words it inserts EWWhiteSpaceTerminal tokens in between which are turned into empty strings. The issue is that the raw value of the From and Subject contain the folding space at the start of the continuation lines:ДЇrom '=?utf-8?b?4ZuX4Zqr4Zqx4ZuP4ZuB4ZuD4Zq+4ZuI4ZuB4ZuW4ZuP4ZuW4Zo=?= =?utf-8?b?seGbiw=?= ' Note the two FFFD placeholders in the From line.

> msg = Parser(policy=fault).parse(StringIO(msgdata)) =?utf-8?b?scqHyoNuya8gyaXKh8Sxyo0gx53Gg8mQc3PHncmvIMqHc8edyocgybnHncaDdW/Kgw=?= Subject: =?utf-8?b?c8qHdcSxb2THnXBvyZQgOC3ihLLiiqXiiKkgx53Kh8qOcS3E?= The From header in the following email headers is not correctly decoded both the subject and from headers contain UTF-8 encoded data encoded with RFC2047 encoded-words, in both cases a multi-byte UTF-8 codepoint has been split between the two encoded-word tokens:ДЇrom: =?utf-8?b?4ZuX4Zqr4Zqx4ZuP4ZuB4ZuD4Zq+4ZuI4ZuB4ZuW4ZuP4ZuW4Zo=?= Jeffrey.Kintscher, barry, era, mjpieters, r.david.murrayД¬reated on 17:54 by mjpieters, last changed 06:45 by Jeffrey.Kintscher. Email.parser / email.policy does not correctly handle multiple RFC2047 encoded-word tokens across RFC5322 folded headers