Setting this to true causes the xmlparser object to buffer textual content returned by Expat to avoid multiple calls to the CharacterDataHandler() callback whenever possible.
If set to a true value, and namespace processing is enabled, the namespace prefix is reported as the third part of the expanded name, separated by the namespace separator.
Expat 2.6.0 introduced a security mechanism called “reparse deferral” where instead of causing denial of service through quadratic runtime from reparsing large tokens, reparsing of unfinished tokens …
If set to a non-zero integer, the parser will report only those attributes which were specified in the document instance and not those which were derived from attribute declarations.
Calling this with a true value for flag (the default) will cause Expat to call the ExternalEntityRefHandler with None for all arguments to allow an alternate DTD to be loaded.