text: # 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(ValueError):
      """Base class for a message defect."""
  
      def __init__(self, line=None):
          if line is not None:
              super().__init__(line)
          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 CloseBoundaryNotFoundDefect(MessageDefect):
      """A start boundary was found, but not the corresponding close boundary."""
  
  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 MissingHeaderBodySeparatorDefect(MessageDefect):
      """Found line with no leading whitespace and no colon before blank line."""
  # XXX: backward compatibility, just in case (it was never emitted).
  MalformedHeaderDefect = MissingHeaderBodySeparatorDefect
  
  class MultipartInvariantViolationDefect(MessageDefect):
      """A message claimed to be a multipart but no subparts were found."""
  
  class InvalidMultipartContentTransferEncodingDefect(MessageDefect):
      """An invalid content transfer encoding was set on the multipart itself."""
  
  class UndecodableBytesDefect(MessageDefect):
      """Header contained bytes that could not be decoded"""
  
  class InvalidBase64PaddingDefect(MessageDefect):
      """base64 encoded sequence had an incorrect length"""
  
  class InvalidBase64CharactersDefect(MessageDefect):
      """base64 encoded sequence had characters not in base64 alphabet"""
  
  class InvalidBase64LengthDefect(MessageDefect):
      """base64 encoded sequence had invalid length (1 mod 4)"""
  
  # These errors are specific to header parsing.
  
  class HeaderDefect(MessageDefect):
      """Base class for a header defect."""
  
      def __init__(self, *args, **kw):
          super().__init__(*args, **kw)
  
  class InvalidHeaderDefect(HeaderDefect):
      """Header is not valid, message gives details."""
  
  class HeaderMissingRequiredValue(HeaderDefect):
      """A header that must have a value had none"""
  
  class NonPrintableDefect(HeaderDefect):
      """ASCII characters outside the ascii-printable range found"""
  
      def __init__(self, non_printables):
          super().__init__(non_printables)
          self.non_printables = non_printables
  
      def __str__(self):
          return ("the following ASCII non-printables found in header: "
              "{}".format(self.non_printables))
  
  class ObsoleteHeaderDefect(HeaderDefect):
      """Header uses syntax declared obsolete by RFC 5322"""
  
  class NonASCIILocalPartDefect(HeaderDefect):
      """local_part contains non-ASCII characters"""
      # This defect only occurs during unicode parsing, not when
      # parsing messages decoded from binary.
  