def adjacency_spectrum(G, weight='weight'):
    """Return eigenvalues of the adjacency matrix of G.

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

    weight : string or None, optional (default='weight')
       The edge data key used to compute each value in the matrix.
       If None, then each edge has weight 1.

    Returns
    -------
    evals : NumPy array
      Eigenvalues

    Notes
    -----
    For MultiGraph/MultiDiGraph, the edges weights are summed.
    See to_numpy_matrix for other options.

    See Also
    --------
    adjacency_matrix
    """
    try:
        import numpy as np
    except __HOLE__:
        raise ImportError(
          "adjacency_spectrum() requires NumPy: http://scipy.org/ ")
    return np.linalg.eigvals(nx.adjacency_matrix(G,weight=weight))

# fixture for nose tests
dataset/ETHPy150Open gkno/gkno_launcher/src/networkx/linalg/spectrum.py/adjacency_spectrum