# Copyright (C) 2001-2006 Python Software Foundation# Author: Barry Warsaw# Contact: email-sig@python.org """email package exception classes."""  class MessageError(Exception):    """Base class for errors in the email package."""  class MessageParseError(MessageError):    """Base class for message parsing errors."""  class HeaderParseError(MessageParseError):    """Error while parsing headers."""  class BoundaryError(MessageParseError):    """Couldn't find terminating boundary."""  class MultipartConversionError(MessageError, TypeError):    """Conversion to a multipart is prohibited."""  class CharsetError(MessageError):    """An illegal charset was given."""  # These are parsing defects which the parser was able to work around.class MessageDefect:    """Base class for a message defect."""     def __init__(self, line=None):        self.line = line class NoBoundaryInMultipartDefect(MessageDefect):    """A message claimed to be a multipart but had no boundary parameter.""" class StartBoundaryNotFoundDefect(MessageDefect):    """The claimed start boundary was never found.""" class FirstHeaderLineIsContinuationDefect(MessageDefect):    """A message had a continuation line as its first header line.""" class MisplacedEnvelopeHeaderDefect(MessageDefect):    """A 'Unix-from' header was found in the middle of a header block.""" class MalformedHeaderDefect(MessageDefect):    """Found a header that was missing a colon, or was otherwise malformed.""" class MultipartInvariantViolationDefect(MessageDefect):    """A message claimed to be a multipart but no subparts were found."""