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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 del_user(self, username):
 """delete a user"""

        ldap_client = self._bind()
        # recover the user dn
        dn = self._byte_p2(self._get_user(self._byte_p2(username), NO_ATTR))
        # delete
        if dn is not None:
            ldap_client.delete_s(dn)
        else:
            ldap_client.unbind_s()
            raise UserDoesntExist(username, self.backend_name)
        ldap_client.unbind_s()