<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_user(self, username):
 """Gest a specific user"""

        ret = {}
        tmp = self._get_user(self._byte_p2(username), ALL_ATTRS)
        if tmp is None:
            raise UserDoesntExist(username, self.backend_name)
        attrs_tmp = tmp[1]
        for attr in attrs_tmp:
            value_tmp = attrs_tmp[attr]
            if len(value_tmp) == 1:
                ret[attr] = value_tmp[0]
            else:
                ret[attr] = value_tmp
        return ret