def get_datatypes_from_ncell(ncell):
    """
    Return the possible datatypes (cl_00, cl_0e, cl_0b, etc.) given a number
    of cells for a pair of tracers

    Parameters:
    -----------
        ncell (int):  Number of Cell for a pair of tracers
    Returns:
    --------
        datatypes (list):  List of data types assotiated to the given degrees
        of freedom

    """
    # Copied from https://github.com/xC-ell/xCell/blob/069c42389f56dfff3a209eef4d05175707c98744/xcell/cls/to_sacc.py#L202-L212
    if ncell == 1:
        cl_types = ['cl_00']
    elif ncell == 2:
        cl_types = ['cl_0e', 'cl_0b']
    elif ncell == 4:
        cl_types = ['cl_ee', 'cl_eb', 'cl_be', 'cl_bb']
    else:
        raise ValueError('ncell does not match 1, 2, or 4.')

    return cl_types