text: """Python part of the warnings subsystem."""
  
  # Note: function level imports should *not* be used
  # in this module as it may cause import lock deadlock.
  # See bug 683658.
  import linecache
  import sys
  import types
  
  __all__ = ["warn", "warn_explicit", "showwarning",
             "formatwarning", "filterwarnings", "simplefilter",
             "resetwarnings", "catch_warnings"]
  
  
  def warnpy3k(message, category=None, stacklevel=1):
      """Issue a deprecation warning for Python 3.x related changes.
  
      Warnings are omitted unless Python is started with the -3 option.
      """
      if sys.py3kwarning:
          if category is None:
              category = DeprecationWarning
          warn(message, category, stacklevel+1)
  
  def _show_warning(message, category, filename, lineno, file=None, line=None):
      """Hook to write a warning to a file; replace if you like."""
      if file is None:
          file = sys.stderr
          if file is None:
              # sys.stderr is None - warnings get lost
              return
      try:
          file.write(formatwarning(message, category, filename, lineno, line))
      except (IOError, UnicodeError):
          pass # the file (probably stderr) is invalid - this warning gets lost.
  # Keep a working version around in case the deprecation of the old API is
  # triggered.
  showwarning = _show_warning
  
  def formatwarning(message, category, filename, lineno, line=None):
      """Function to format a warning the standard way."""
      try:
          unicodetype = unicode
      except NameError:
          unicodetype = ()
      template = "%s: %s: %s\n"
      try:
          message = str(message)
      except UnicodeEncodeError:
          template = unicode(template)
      s = template % (lineno, category.__name__, message)
      line = linecache.getline(filename, lineno) if line is None else line
      if line:
          line = line.strip()
          if isinstance(s, unicodetype) and isinstance(line, str):
              line = unicode(line, 'latin1')
          s += "  %s\n" % line
      if isinstance(s, unicodetype) and isinstance(filename, str):
          enc = sys.getfilesystemencoding()
          if enc:
              try:
                  filename = unicode(filename, enc)
              except UnicodeDecodeError:
                  pass
      s = "%s:%s" % (filename, s)
      return s
  
  def filterwarnings(action, message="", category=Warning, module="", lineno=0,
                     append=0):
      """Insert an entry into the list of warnings filters (at the front).
  
      'action' -- one of "error", "ignore", "always", "default", "module",
                  or "once"
      'message' -- a regex that the warning message must match
      'category' -- a class that the warning must be a subclass of
      'module' -- a regex that the module name must match
      'lineno' -- an integer line number, 0 matches all warnings
      'append' -- if true, append to the list of filters
      """
      import re
      assert action in ("error", "ignore", "always", "default", "module",
                        "once"), "invalid action: %r" % (action,)
      assert isinstance(message, basestring), "message must be a string"
      assert isinstance(category, (type, types.ClassType)), \
             "category must be a class"
      assert issubclass(category, Warning), "category must be a Warning subclass"
      assert isinstance(module, basestring), "module must be a string"
      assert isinstance(lineno, int) and lineno >= 0, \
             "lineno must be an int >= 0"
      item = (action, re.compile(message, re.I), category,
              re.compile(module), lineno)
      if append:
          filters.append(item)
      else:
          filters.insert(0, item)
  
  def simplefilter(action, category=Warning, lineno=0, append=0):
      """Insert a simple entry into the list of warnings filters (at the front).
  
      A simple filter matches all modules and messages.
      'action' -- one of "error", "ignore", "always", "default", "module",
                  or "once"
      'category' -- a class that the warning must be a subclass of
      'lineno' -- an integer line number, 0 matches all warnings
      'append' -- if true, append to the list of filters
      """
      assert action in ("error", "ignore", "always", "default", "module",
                        "once"), "invalid action: %r" % (action,)
      assert isinstance(lineno, int) and lineno >= 0, \
             "lineno must be an int >= 0"
      item = (action, None, category, None, lineno)
      if append:
          filters.append(item)
      else:
          filters.insert(0, item)
  
  def resetwarnings():
      """Clear the list of warning filters, so that no filters are active."""
      filters[:] = []
  
  class _OptionError(Exception):
      """Exception used by option processing helpers."""
      pass
  
  # Helper to process -W options passed via sys.warnoptions
  def _processoptions(args):
      for arg in args:
          try:
              _setoption(arg)
          except _OptionError, msg:
              print >>sys.stderr, "Invalid -W option ignored:", msg
  
  # Helper for _processoptions()
  def _setoption(arg):
      import re
      parts = arg.split(':')
      if len(parts) > 5:
          raise _OptionError("too many fields (max 5): %r" % (arg,))
      while len(parts) < 5:
          parts.append('')
      action, message, category, module, lineno = [s.strip()
                                                   for s in parts]
      action = _getaction(action)
      message = re.escape(message)
      category = _getcategory(category)
      module = re.escape(module)
      if module:
          module = module + '$'
      if lineno:
          try:
              lineno = int(lineno)
              if lineno < 0:
                  raise ValueError
          except (ValueError, OverflowError):
              raise _OptionError("invalid lineno %r" % (lineno,))
      else:
          lineno = 0
      filterwarnings(action, message, category, module, lineno)
  
  # Helper for _setoption()
  def _getaction(action):
      if not action:
          return "default"
      if action == "all": return "always" # Alias
      for a in ('default', 'always', 'ignore', 'module', 'once', 'error'):
          if a.startswith(action):
              return a
      raise _OptionError("invalid action: %r" % (action,))
  
  # Helper for _setoption()
  def _getcategory(category):
      import re
      if not category:
          return Warning
      if re.match("^[a-zA-Z0-9_]+$", category):
          try:
              cat = eval(category)
          except NameError:
              raise _OptionError("unknown warning category: %r" % (category,))
      else:
          i = category.rfind(".")
          module = category[:i]
          klass = category[i+1:]
          try:
              if not module:
                  raise ImportError   # instead of the ValueError we'd get
              m = __import__(module, None, None, [klass])
          except ImportError:
              raise _OptionError("invalid module name: %r" % (module,))
          try:
              cat = getattr(m, klass)
          except AttributeError:
              raise _OptionError("unknown warning category: %r" % (category,))
      if not issubclass(cat, Warning):
          raise _OptionError("invalid warning category: %r" % (category,))
      return cat
  
  
  # Code typically replaced by _warnings
  def warn(message, category=None, stacklevel=1):
      """Issue a warning, or maybe ignore it or raise an exception."""
      # Check if message is already a Warning object
      if isinstance(message, Warning):
          category = message.__class__
      # Check category argument
      if category is None:
          category = UserWarning
      assert issubclass(category, Warning)
      # Get context information
      try:
          caller = sys._getframe(stacklevel)
      except ValueError:
          globals = sys.__dict__
          lineno = 1
      else:
          globals = caller.f_globals
          lineno = caller.f_lineno
      if '__name__' in globals:
          module = globals['__name__']
      else:
          module = "<string>"
      filename = globals.get('__file__')
      if filename:
          fnl = filename.lower()
          if fnl.endswith((".pyc", ".pyo")):
              filename = filename[:-1]
      else:
          if module == "__main__":
              try:
                  filename = sys.argv[0]
              except AttributeError:
                  # embedded interpreters don't have sys.argv, see bug #839151
                  filename = '__main__'
          if not filename:
              filename = module
      registry = globals.setdefault("__warningregistry__", {})
      warn_explicit(message, category, filename, lineno, module, registry,
                    globals)
  
  def warn_explicit(message, category, filename, lineno,
                    module=None, registry=None, module_globals=None):
      lineno = int(lineno)
      if module is None:
          module = filename or "<unknown>"
          if module[-3:].lower() == ".py":
              module = module[:-3] # XXX What about leading pathname?
      if registry is None:
          registry = {}
      if isinstance(message, Warning):
          text = str(message)
          category = message.__class__
      else:
          text = message
          message = category(message)
      key = (text, category, lineno)
      # Quick test for common case
      if registry.get(key):
          return
      # Search the filters
      for item in filters:
          action, msg, cat, mod, ln = item
          if ((msg is None or msg.match(text)) and
              issubclass(category, cat) and
              (mod is None or mod.match(module)) and
              (ln == 0 or lineno == ln)):
              break
      else:
          action = defaultaction
      # Early exit actions
      if action == "ignore":
          registry[key] = 1
          return
  
      # Prime the linecache for formatting, in case the
      # "file" is actually in a zipfile or something.
      linecache.getlines(filename, module_globals)
  
      if action == "error":
          raise message
      # Other actions
      if action == "once":
          registry[key] = 1
          oncekey = (text, category)
          if onceregistry.get(oncekey):
              return
          onceregistry[oncekey] = 1
      elif action == "always":
          pass
      elif action == "module":
          registry[key] = 1
          altkey = (text, category, 0)
          if registry.get(altkey):
              return
          registry[altkey] = 1
      elif action == "default":
          registry[key] = 1
      else:
          # Unrecognized actions are errors
          raise RuntimeError(
                "Unrecognized action (%r) in warnings.filters:\n %s" %
                (action, item))
      # Print message and context
      showwarning(message, category, filename, lineno)
  
  
  class WarningMessage(object):
  
      """Holds the result of a single showwarning() call."""
  
      _WARNING_DETAILS = ("message", "category", "filename", "lineno", "file",
                          "line")
  
      def __init__(self, message, category, filename, lineno, file=None,
                      line=None):
          self.message = message
          self.category = category
          self.filename = filename
          self.lineno = lineno
          self.file = file
          self.line = line
          self._category_name = category.__name__ if category else None
  
      def __str__(self):
          return ("{message : %r, category : %r, filename : %r, lineno : %s, "
                      "line : %r}" % (self.message, self._category_name,
                                      self.filename, self.lineno, self.line))
  
  
  class catch_warnings(object):
  
      """A context manager that copies and restores the warnings filter upon
      exiting the context.
  
      The 'record' argument specifies whether warnings should be captured by a
      custom implementation of warnings.showwarning() and be appended to a list
      returned by the context manager. Otherwise None is returned by the context
      manager. The objects appended to the list are arguments whose attributes
      mirror the arguments to showwarning().
  
      The 'module' argument is to specify an alternative module to the module
      named 'warnings' and imported under that name. This argument is only useful
      when testing the warnings module itself.
  
      """
  
      def __init__(self, record=False, module=None):
          """Specify whether to record warnings and if an alternative module
          should be used other than sys.modules['warnings'].
  
          For compatibility with Python 3.0, please consider all arguments to be
          keyword-only.
  
          """
          self._record = record
          self._module = sys.modules['warnings'] if module is None else module
          self._entered = False
  
      def __repr__(self):
          args = []
          if self._record:
              args.append("record=True")
          if self._module is not sys.modules['warnings']:
              args.append("module=%r" % self._module)
          name = type(self).__name__
          return "%s(%s)" % (name, ", ".join(args))
  
      def __enter__(self):
          if self._entered:
              raise RuntimeError("Cannot enter %r twice" % self)
          self._entered = True
          self._filters = self._module.filters
          self._module.filters = self._filters[:]
          self._showwarning = self._module.showwarning
          if self._record:
              log = []
              def showwarning(*args, **kwargs):
                  log.append(WarningMessage(*args, **kwargs))
              self._module.showwarning = showwarning
              return log
          else:
              return None
  
      def __exit__(self, *exc_info):
          if not self._entered:
              raise RuntimeError("Cannot exit %r without entering first" % self)
          self._module.filters = self._filters
          self._module.showwarning = self._showwarning
  
  
  # filters contains a sequence of filter 5-tuples
  # The components of the 5-tuple are:
  # - an action: error, ignore, always, default, module, or once
  # - a compiled regex that must match the warning message
  # - a class representing the warning category
  # - a compiled regex that must match the module that is being warned
  # - a line number for the line being warning, or 0 to mean any line
  # If either if the compiled regexs are None, match anything.
  _warnings_defaults = False
  try:
      from _warnings import (filters, default_action, once_registry,
                              warn, warn_explicit)
      defaultaction = default_action
      onceregistry = once_registry
      _warnings_defaults = True
  except ImportError:
      filters = []
      defaultaction = "default"
      onceregistry = {}
  
  
  # Module initialization
  _processoptions(sys.warnoptions)
  if not _warnings_defaults:
      silence = [ImportWarning, PendingDeprecationWarning]
      # Don't silence DeprecationWarning if -3 or -Q was used.
      if not sys.py3kwarning and not sys.flags.division_warning:
          silence.append(DeprecationWarning)
      for cls in silence:
          simplefilter("ignore", category=cls)
      bytes_warning = sys.flags.bytes_warning
      if bytes_warning > 1:
          bytes_action = "error"
      elif bytes_warning:
          bytes_action = "default"
      else:
          bytes_action = "ignore"
      simplefilter(bytes_action, category=BytesWarning, append=1)
  del _warnings_defaults
  