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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 candidate_pairs_iter(self):
 """Iterator over candidate pairs of nodes in G1 and G2."""

        # All computations are done using the current state!
        G2_nodes = self.G2_nodes

        # First we compute the inout-terminal sets.
        T1_inout = set(self.inout_1.keys()) - set(self.core_1.keys())
        T2_inout = set(self.inout_2.keys()) - set(self.core_2.keys())

        # If T1_inout and T2_inout are both nonempty.
        # P(s) = T1_inout x {min T2_inout}
        if T1_inout and T2_inout:
            for node in T1_inout:
                yield node, min(T2_inout)
        else:
            # First we determine the candidate node for G2
            other_node = min(G2_nodes - set(self.core_2))
            host_nodes = self.valid_nodes if other_node == 0 else self.G1.nodes()
            for node in host_nodes:
                if node not in self.core_1:
                    yield node, other_node