email.errors: Exception and Defect classes

Source code: Lib/email/errors.py

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The following exception classes are defined in the email.errors module:

exception email.errors.MessageError

This is the base class for all exceptions that the email package can raise. It is derived from the standard Exception class and defines no additional methods.

exception email.errors.MessageParseError

This is the base class for exceptions raised by the Parser class. It is derived from MessageError. This class is also used internally by the parser used by headerregistry.

exception email.errors.HeaderParseError

Raised under some error conditions when parsing the RFC 5322 headers of a message, this class is derived from MessageParseError. The set_boundary() method will raise this error if the content type is unknown when the method is called. Header may raise this error for certain base64 decoding errors, and when an attempt is made to create a header that appears to contain an embedded header (that is, there is what is supposed to be a continuation line that has no leading whitespace and looks like a header).

exception email.errors.BoundaryError

Deprecated and no longer used.

exception email.errors.MultipartConversionError

Raised if the attach() method is called on an instance of a class derived from MIMENonMultipart (e.g. MIMEImage). MultipartConversionError multiply inherits from MessageError and the built-in TypeError.

exception email.errors.HeaderWriteError

Raised when an error occurs when the generator outputs headers.

exception email.errors.MessageDefect

This is the base class for all defects found when parsing email messages. It is derived from ValueError.

exception email.errors.HeaderDefect

This is the base class for all defects found when parsing email headers. It is derived from MessageDefect.

Here is the list of the defects that the FeedParser can find while parsing messages. Note that the defects are added to the message where the problem was found, so for example, if a message nested inside a multipart/alternative had a malformed header, that nested message object would have a defect, but the containing messages would not.

All defect classes are subclassed from email.errors.MessageDefect.

exception email.errors.NoBoundaryInMultipartDefect

A message claimed to be a multipart, but had no boundary parameter.

exception email.errors.StartBoundaryNotFoundDefect

The start boundary claimed in the Content-Type header was never found.

exception email.errors.CloseBoundaryNotFoundDefect

A start boundary was found, but no corresponding close boundary was ever found.

Added in version 3.3.

exception email.errors.FirstHeaderLineIsContinuationDefect

The message had a continuation line as its first header line.

exception email.errors.MisplacedEnvelopeHeaderDefect

A “Unix From” header was found in the middle of a header block.

exception email.errors.MissingHeaderBodySeparatorDefect

A line was found while parsing headers that had no leading white space but contained no ‘:’. Parsing continues assuming that the line represents the first line of the body.

Added in version 3.3.

exception email.errors.MalformedHeaderDefect

A header was found that was missing a colon, or was otherwise malformed.

Deprecated since version 3.3: This defect has not been used for several Python versions.

exception email.errors.MultipartInvariantViolationDefect

A message claimed to be a multipart, but no subparts were found. Note that when a message has this defect, its is_multipart() method may return False even though its content type claims to be multipart.

exception email.errors.InvalidBase64PaddingDefect

When decoding a block of base64 encoded bytes, the padding was not correct. Enough padding is added to perform the decode, but the resulting decoded bytes may be invalid.

exception email.errors.InvalidBase64CharactersDefect

When decoding a block of base64 encoded bytes, characters outside the base64 alphabet were encountered. The characters are ignored, but the resulting decoded bytes may be invalid.

exception email.errors.InvalidBase64LengthDefect

When decoding a block of base64 encoded bytes, the number of non-padding base64 characters was invalid (1 more than a multiple of 4). The encoded block was kept as-is.

exception email.errors.InvalidDateDefect

When decoding an invalid or unparsable date field. The original value is kept as-is.