Retrieve relevant information at construction time, as it may be lost
when the exception is printed.

Break cycle involving expat parser in close().
Add lex handler support to SAX2 pyexpat

version of Python.  ;-(

now, so can't find number).

than tuples.

expatreader: Use the error handler instead of raising exception directly.

the InputSource.

callers of feed will get a SAXException.
In close, feed the last chunk first before calling endDocument, so that
the parser may report errors before the end of the document. Don't do
anything in a nested parser.
Don't call endDocument in parse; that will be called in close.
Use self._source for finding the SystemID; XML_GetBase will be cleared in
case of an error.

ImportError, and a missing driver.

caused the drive letter to cause urlopen() to think it was an unrecognized
URL scheme.  This only passes system ids to urlopen() if the file does not
exist.  It works on Windows & Unix.

It should work everywhere else as well.

xml.sax: Fix parse and parseString not to rely on ExpatParser
         Greatly simplify import logic by using __import__
saxutils: Support Unicode strings and files as parameters to
          prepare_input_source

Tiny bug fix to expatreader.py (endDocument was only called after errors).

Bug fixes to XMLFilterBase (wrong ignorableWhitespace signature and
did not inherit set*Handler methods from XMLReader.)

Add support for parsing already-opened files.  Make sure the parse()
method closes exactly those files that it opens.

Modified by FLD for better conformance to the Python style guide.

This closes SourceForge patch #101512.