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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 obs_groups(self):
 """get the observation groups Returns ------- obs_groups : list a list of unique observation groups """

        og = list(self.observation_data.groupby("obgnme").groups.keys())
        #og = list(map(pst_utils.SFMT, og))
        return og