cpython/Lib/xml/sax/__init__.py
Pablo Galindo 293dd23477
Remove binding of captured exceptions when not used to reduce the chances of creating cycles (GH-17246)
Capturing exceptions into names can lead to reference cycles though the __traceback__ attribute of the exceptions in some obscure cases that have been reported previously and fixed individually. As these variables are not used anyway, we can remove the binding to reduce the chances of creating reference cycles.

See for example GH-13135
2019-11-19 21:34:03 +00:00

108 lines
3.6 KiB
Python

"""Simple API for XML (SAX) implementation for Python.
This module provides an implementation of the SAX 2 interface;
information about the Java version of the interface can be found at
http://www.megginson.com/SAX/. The Python version of the interface is
documented at <...>.
This package contains the following modules:
handler -- Base classes and constants which define the SAX 2 API for
the 'client-side' of SAX for Python.
saxutils -- Implementation of the convenience classes commonly used to
work with SAX.
xmlreader -- Base classes and constants which define the SAX 2 API for
the parsers used with SAX for Python.
expatreader -- Driver that allows use of the Expat parser with SAX.
"""
from .xmlreader import InputSource
from .handler import ContentHandler, ErrorHandler
from ._exceptions import SAXException, SAXNotRecognizedException, \
SAXParseException, SAXNotSupportedException, \
SAXReaderNotAvailable
def parse(source, handler, errorHandler=ErrorHandler()):
parser = make_parser()
parser.setContentHandler(handler)
parser.setErrorHandler(errorHandler)
parser.parse(source)
def parseString(string, handler, errorHandler=ErrorHandler()):
import io
if errorHandler is None:
errorHandler = ErrorHandler()
parser = make_parser()
parser.setContentHandler(handler)
parser.setErrorHandler(errorHandler)
inpsrc = InputSource()
if isinstance(string, str):
inpsrc.setCharacterStream(io.StringIO(string))
else:
inpsrc.setByteStream(io.BytesIO(string))
parser.parse(inpsrc)
# this is the parser list used by the make_parser function if no
# alternatives are given as parameters to the function
default_parser_list = ["xml.sax.expatreader"]
# tell modulefinder that importing sax potentially imports expatreader
_false = 0
if _false:
import xml.sax.expatreader
import os, sys
if not sys.flags.ignore_environment and "PY_SAX_PARSER" in os.environ:
default_parser_list = os.environ["PY_SAX_PARSER"].split(",")
del os
_key = "python.xml.sax.parser"
if sys.platform[:4] == "java" and sys.registry.containsKey(_key):
default_parser_list = sys.registry.getProperty(_key).split(",")
def make_parser(parser_list=()):
"""Creates and returns a SAX parser.
Creates the first parser it is able to instantiate of the ones
given in the iterable created by chaining parser_list and
default_parser_list. The iterables must contain the names of Python
modules containing both a SAX parser and a create_parser function."""
for parser_name in list(parser_list) + default_parser_list:
try:
return _create_parser(parser_name)
except ImportError:
import sys
if parser_name in sys.modules:
# The parser module was found, but importing it
# failed unexpectedly, pass this exception through
raise
except SAXReaderNotAvailable:
# The parser module detected that it won't work properly,
# so try the next one
pass
raise SAXReaderNotAvailable("No parsers found", None)
# --- Internal utility methods used by make_parser
if sys.platform[ : 4] == "java":
def _create_parser(parser_name):
from org.python.core import imp
drv_module = imp.importName(parser_name, 0, globals())
return drv_module.create_parser()
else:
def _create_parser(parser_name):
drv_module = __import__(parser_name,{},{},['create_parser'])
return drv_module.create_parser()
del sys