def zip(self, destination=None, overwrite=True):
        if destination is None:
            if self.name is not None:
                destination = self.name % "%s.zip"
            else:
                raise ValueError("Package name or destination is required.")
        if file_exists(destination) and not overwrite:
            raise ValueError("Destination '%s' already exists." % destination)
        filelist = self.files.copy()
        for dest, loc in filelist.items():
            if not file_exists(loc):
                del(self.files[dest])
        if len(self.files) > 0:
            z = zipfile.ZipFile(destination, "w")
            for dest, loc in self.files.items():
                z.write(loc, dest)
            z.close()
        self.zip_path = destination
        return file_exists(destination)
dataset/ETHPy150Open iron-io/iron_worker_python/iron_worker.py/CodePackage.zip/swapped operands of `%`