def is_k_regular(G, k):
    """Determines whether the graph ``G`` is a k-regular graph.

    A k-regular graph is a graph where each vertex has degree k.

    Parameters
    ----------
    G : NetworkX graph

    Returns
    -------
    bool
        Whether the given graph is k-regular.

    """
    return all(d == k for n, d in G.degree)