Returns the path of data files, which are installed to the package directory.

def get_data_files():
    """
    Returns the path of data files, which are installed to the package directory.
    """
    import os

    path = os.path.dirname(__file__)
    path = os.path.join(path, 'data')
    r = dict(
        Alpha_inf_hyrec_file = os.path.join(path, 'hyrec', 'Alpha_inf.dat'),
        R_inf_hyrec_file = os.path.join(path, 'hyrec', 'R_inf.dat'),
        two_photon_tables_hyrec_file = os.path.join(path, 'hyrec', 'two_photon_tables.dat'),
        sBBN_file = os.path.join(path, 'bbn', 'sBBN.dat'),
    )
    return r