def _quote(x):
	if type(x) == types.StringType:
		x = "'" + string.replace(str(x), "'", "''") + "'"
	elif type(x) in (types.IntType, types.LongType, types.FloatType):
		pass
	elif x is None:
		x = 'NULL'
	elif isinstance(x, datetime.date):
		x = "{d'%04d-%02d-%02d'}" % (x.year, x.month, x.day)
	elif hasattr(x, '__pg_repr__'):
		x = x.__pg_repr__()
	else:
		#print "didn't like " + x + " " + str(type(x))
		raise InterfaceError, 'do not know how to handle type %s' % type(x)