13.5.5 Expat error constants

##
13.5.5 Expat error constants

The following constants are provided in the `errors` object of the `xml.parsers.expat` module. These constants are useful in interpreting some of the attributes of the `ExpatError` exception objects raised when an error has occurred.

The `errors` object has the following attributes:

`XML_ERROR_ASYNC_ENTITY`

`XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF`
  An entity reference in an attribute value referred to an external entity instead of an internal entity.

`XML_ERROR_BAD_CHAR_REF`
  A character reference referred to a character which is illegal in XML (for example, character `0`, or ``&#0;`').

`XML_ERROR_BINARY_ENTITY_REF`
  An entity reference referred to an entity which was declared with a notation, so cannot be parsed.

`XML_ERROR_DUPLICATE_ATTRIBUTE`
  An attribute was used more than once in a start tag.

`XML_ERROR_INCORRECT_ENCODING`

`XML_ERROR_INVALID_TOKEN`
  Raised when an input byte could not properly be assigned to a character; for example, a NUL byte (value `0`) in a UTF-8 input stream.

`XML_ERROR_JUNK_AFTER_DOC_ELEMENT`
  Something other than whitespace occurred after the document element.

`XML_ERROR_MISPLACED_XML_PI`
  An XML declaration was found somewhere other than the start of the input data.

`XML_ERROR_NO_ELEMENTS`
  The document contains no elements (XML requires all documents to contain exactly one top-level element)..

`XML_ERROR_NO_MEMORY`
  Expat was not able to allocate memory internally.

`XML_ERROR_PARAM_ENTITY_REF`
  A parameter entity reference was found where it was not allowed.

`XML_ERROR_PARTIAL_CHAR`
  An incomplete character was found in the input.

`XML_ERROR_RECURSIVE_ENTITY_REF`
  An entity reference contained another reference to the same entity; possibly via a different name, and possibly indirectly.

`XML_ERROR_SYNTAX`
  Some unspecified syntax error was encountered.

`XML_ERROR_TAG_MISMATCH`
  An end tag did not match the innermost open start tag.

`XML_ERROR_UNCLOSED_TOKEN`
  Some token (such as a start tag) was not closed before the end of the stream or the next token was encountered.

`XML_ERROR_UNDEFINED_ENTITY`
  A reference was made to a entity which was not defined.

`XML_ERROR_UNKNOWN_ENCODING`
  The document encoding is not supported by Expat.

`XML_ERROR_UNCLOSED_CDATA_SECTION`
  A CDATA marked section was not closed.

`XML_ERROR_EXTERNAL_ENTITY_HANDLING`

`XML_ERROR_NOT_STANDALONE`
  The parser determined that the document was not ``standalone'' though it declared itself to be in the XML declaration, and the `NotStandaloneHandler` was set and returned `0`.

`XML_ERROR_UNEXPECTED_STATE`

`XML_ERROR_ENTITY_DECLARED_IN_PE`

`XML_ERROR_FEATURE_REQUIRES_XML_DTD`
  An operation was requested that requires DTD support to be compiled in, but Expat was configured without DTD support. This should never be reported by a standard build of the `xml.parsers.expat` module.

`XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING`
  A behavioral change was requested after parsing started that can only be changed before parsing has started. This is (currently) only raised by `UseForeignDTD()`.

`XML_ERROR_UNBOUND_PREFIX`
  An undeclared prefix was found when namespace processing was enabled.

`XML_ERROR_UNDECLARING_PREFIX`
  The document attempted to remove the namespace declaration associated with a prefix.

`XML_ERROR_INCOMPLETE_PE`
  A parameter entity contained incomplete markup.

`XML_ERROR_XML_DECL`
  The document contained no document element at all.

`XML_ERROR_TEXT_DECL`
  There was an error parsing a text declaration in an external entity.

`XML_ERROR_PUBLICID`
  Characters were found in the public id that are not allowed.

`XML_ERROR_SUSPENDED`
  The requested operation was made on a suspended parser, but isn't allowed. This includes attempts to provide additional input or to stop the parser.

`XML_ERROR_NOT_SUSPENDED`
  An attempt to resume the parser was made when the parser had not been suspended.

`XML_ERROR_ABORTED`
  This should not be reported to Python applications.

`XML_ERROR_FINISHED`
  The requested operation was made on a parser which was finished parsing input, but isn't allowed. This includes attempts to provide additional input or to stop the parser.

`XML_ERROR_SUSPEND_PE`