re._pattern_type.py

	def _getregex(self):
		"""
		The RegexObject that is used for finding substrings in the source name
		that should be replaced by substitute.
		
		You may set this property either to a RegexObject or to a string. The
		latter will automatically be supplied to re.compile().
		
		Defaults to '[A-Za-z0-9.-]'.
		"""
		return self._regex

	def _setregex(self, value):
		# Is this the best way to type check value?
		if isinstance(value, re._pattern_type):
			self._regex = value
		elif isinstance(value, str):
			self._regex = re.compile(value)
		else:
			raise TypeError('regex has to be a RegexObject or a string')

	regex = property(_getregex, _setregex)