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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def default_job_name(self):
 """Slurm job name if not already specified in the `sbatch` section"""

        name = ''
        if not self.root.existing_campaign:
            campaign_file = osp.basename(self.root.campaign_file)
            campaign = osp.splitext(campaign_file)[0]
            name += campaign + '/'
        name += self.tag
        return name