Simple wrapper to make Roofit workspace manipulation more safe with python

safe_roofit.py

def safe_factory(func):
    def wrapper(self, *args):
        result = func(self, *args)
        if not result:
            raise ValueError('invalid factory input "%s"' % args)
        return result
    return wrapper

ROOT.RooWorkspace.factory = safe_factory(ROOT.RooWorkspace.factory)

def safe_decorator(func):
    def wrapper(self, *args):
        result = func(self, *args)
        if not result:
            raise ValueError('cannot find %s' % args[0])
        return result
    return wrapper

ROOT.RooWorkspace.data = safe_decorator(ROOT.RooWorkspace.data)
ROOT.RooWorkspace.obj = safe_decorator(ROOT.RooWorkspace.obj)
ROOT.RooWorkspace.var = safe_decorator(ROOT.RooWorkspace.var)
ROOT.RooWorkspace.pdf = safe_decorator(ROOT.RooWorkspace.pdf)