def build(self,**kwargs):
        pattern = kwargs.get('pattern', self.__class__._pattern)
        try :
            self.parser = re.compile(pattern)
        except :
            raise ValueError, pattern % "cannot build Token Parser from pattern %r. you must set the _pattern attribute to a valid regular expression"
dataset/ETHPy150Open CountZer0/PipelineConstructionSet/python/maya/site-packages/pymel-1.0.5/pymel/util/objectParser.py/TokenParser.build/swapped operands of `%`