1 :mod:`email.errors`: Exception and Defect classes 2 ------------------------------------------------- 3 4 .. module:: email.errors 5 :synopsis: The exception classes used by the email package. 6 7 **Source code:** :source:`Lib/email/errors.py` 8 9 -------------- 10 11 The following exception classes are defined in the :mod:`email.errors` module: 12 13 14 .. exception:: MessageError() 15 16 This is the base class for all exceptions that the :mod:`email` package can 17 raise. It is derived from the standard :exc:`Exception` class and defines no 18 additional methods. 19 20 21 .. exception:: MessageParseError() 22 23 This is the base class for exceptions raised by the 24 :class:`~email.parser.Parser` class. It is derived from 25 :exc:`MessageError`. This class is also used internally by the parser used 26 by :mod:`~email.headerregistry`. 27 28 29 .. exception:: HeaderParseError() 30 31 Raised under some error conditions when parsing the :rfc:`5322` headers of a 32 message, this class is derived from :exc:`MessageParseError`. The 33 :meth:`~email.message.EmailMessage.set_boundary` method will raise this 34 error if the content type is unknown when the method is called. 35 :class:`~email.header.Header` may raise this error for certain base64 36 decoding errors, and when an attempt is made to create a header that appears 37 to contain an embedded header (that is, there is what is supposed to be a 38 continuation line that has no leading whitespace and looks like a header). 39 40 41 .. exception:: BoundaryError() 42 43 Deprecated and no longer used. 44 45 46 .. exception:: MultipartConversionError() 47 48 Raised when a payload is added to a :class:`~email.message.Message` object 49 using :meth:`add_payload`, but the payload is already a scalar and the 50 message's :mailheader:`Content-Type` main type is not either 51 :mimetype:`multipart` or missing. :exc:`MultipartConversionError` multiply 52 inherits from :exc:`MessageError` and the built-in :exc:`TypeError`. 53 54 Since :meth:`Message.add_payload` is deprecated, this exception is rarely 55 raised in practice. However the exception may also be raised if the 56 :meth:`~email.message.Message.attach` 57 method is called on an instance of a class derived from 58 :class:`~email.mime.nonmultipart.MIMENonMultipart` (e.g. 59 :class:`~email.mime.image.MIMEImage`). 60 61 62 Here is the list of the defects that the :class:`~email.parser.FeedParser` 63 can find while parsing messages. Note that the defects are added to the message 64 where the problem was found, so for example, if a message nested inside a 65 :mimetype:`multipart/alternative` had a malformed header, that nested message 66 object would have a defect, but the containing messages would not. 67 68 All defect classes are subclassed from :class:`email.errors.MessageDefect`. 69 70 * :class:`NoBoundaryInMultipartDefect` -- A message claimed to be a multipart, 71 but had no :mimetype:`boundary` parameter. 72 73 * :class:`StartBoundaryNotFoundDefect` -- The start boundary claimed in the 74 :mailheader:`Content-Type` header was never found. 75 76 * :class:`CloseBoundaryNotFoundDefect` -- A start boundary was found, but 77 no corresponding close boundary was ever found. 78 79 .. versionadded:: 3.3 80 81 * :class:`FirstHeaderLineIsContinuationDefect` -- The message had a continuation 82 line as its first header line. 83 84 * :class:`MisplacedEnvelopeHeaderDefect` - A "Unix From" header was found in the 85 middle of a header block. 86 87 * :class:`MissingHeaderBodySeparatorDefect` - A line was found while parsing 88 headers that had no leading white space but contained no ':'. Parsing 89 continues assuming that the line represents the first line of the body. 90 91 .. versionadded:: 3.3 92 93 * :class:`MalformedHeaderDefect` -- A header was found that was missing a colon, 94 or was otherwise malformed. 95 96 .. deprecated:: 3.3 97 This defect has not been used for several Python versions. 98 99 * :class:`MultipartInvariantViolationDefect` -- A message claimed to be a 100 :mimetype:`multipart`, but no subparts were found. Note that when a message 101 has this defect, its :meth:`~email.message.Message.is_multipart` method may 102 return false even though its content type claims to be :mimetype:`multipart`. 103 104 * :class:`InvalidBase64PaddingDefect` -- When decoding a block of base64 105 enocded bytes, the padding was not correct. Enough padding is added to 106 perform the decode, but the resulting decoded bytes may be invalid. 107 108 * :class:`InvalidBase64CharactersDefect` -- When decoding a block of base64 109 enocded bytes, characters outside the base64 alphebet were encountered. 110 The characters are ignored, but the resulting decoded bytes may be invalid. 111
