Read a 1D Histogram.

def get_hist(rfile, histname, get_overflow=False):
    """Read a 1D Histogram."""
    import root_numpy as rnp

    rfile = open_rfile(rfile)
    hist = rfile[histname]
    xlims = np.array(list(hist.xedges()))
    bin_values = rnp.hist2array(hist, include_overflow=get_overflow)
    rfile.close()
    return bin_values, xlims