1 :mod:`email`: Exception and Defect classes
2 ------------------------------------------
4 .. module:: email.errors
5 :synopsis: The exception classes used by the email package.
8 The following exception classes are defined in the :mod:`email.errors` module:
11 .. exception:: MessageError()
13 This is the base class for all exceptions that the :mod:`email` package can
14 raise. It is derived from the standard :exc:`Exception` class and defines no
18 .. exception:: MessageParseError()
20 This is the base class for exceptions thrown by the :class:`Parser` class. It
21 is derived from :exc:`MessageError`.
24 .. exception:: HeaderParseError()
26 Raised under some error conditions when parsing the :rfc:`2822` headers of a
27 message, this class is derived from :exc:`MessageParseError`. It can be raised
28 from the :meth:`Parser.parse` or :meth:`Parser.parsestr` methods.
30 Situations where it can be raised include finding an envelope header after the
31 first :rfc:`2822` header of the message, finding a continuation line before the
32 first :rfc:`2822` header is found, or finding a line in the headers which is
33 neither a header or a continuation line.
36 .. exception:: BoundaryError()
38 Raised under some error conditions when parsing the :rfc:`2822` headers of a
39 message, this class is derived from :exc:`MessageParseError`. It can be raised
40 from the :meth:`Parser.parse` or :meth:`Parser.parsestr` methods.
42 Situations where it can be raised include not being able to find the starting or
43 terminating boundary in a :mimetype:`multipart/\*` message when strict parsing
47 .. exception:: MultipartConversionError()
49 Raised when a payload is added to a :class:`Message` object using
50 :meth:`add_payload`, but the payload is already a scalar and the message's
51 :mailheader:`Content-Type` main type is not either :mimetype:`multipart` or
52 missing. :exc:`MultipartConversionError` multiply inherits from
53 :exc:`MessageError` and the built-in :exc:`TypeError`.
55 Since :meth:`Message.add_payload` is deprecated, this exception is rarely raised
56 in practice. However the exception may also be raised if the :meth:`attach`
57 method is called on an instance of a class derived from
58 :class:`MIMENonMultipart` (e.g. :class:`MIMEImage`).
60 Here's the list of the defects that the :class:`FeedParser` can find while
61 parsing messages. Note that the defects are added to the message where the
62 problem was found, so for example, if a message nested inside a
63 :mimetype:`multipart/alternative` had a malformed header, that nested message
64 object would have a defect, but the containing messages would not.
66 All defect classes are subclassed from :class:`email.errors.MessageDefect`, but
67 this class is *not* an exception!
70 All the defect classes were added.
72 * :class:`NoBoundaryInMultipartDefect` -- A message claimed to be a multipart,
73 but had no :mimetype:`boundary` parameter.
75 * :class:`StartBoundaryNotFoundDefect` -- The start boundary claimed in the
76 :mailheader:`Content-Type` header was never found.
78 * :class:`FirstHeaderLineIsContinuationDefect` -- The message had a continuation
79 line as its first header line.
81 * :class:`MisplacedEnvelopeHeaderDefect` - A "Unix From" header was found in the
82 middle of a header block.
84 * :class:`MalformedHeaderDefect` -- A header was found that was missing a colon,
85 or was otherwise malformed.
87 * :class:`MultipartInvariantViolationDefect` -- A message claimed to be a
88 :mimetype:`multipart`, but no subparts were found. Note that when a message has
89 this defect, its :meth:`is_multipart` method may return false even though its
90 content type claims to be :mimetype:`multipart`.