def _comp_suffix(s):
    """
    Returns the comparison operator suffix given a search field.
    This does not include the `__` (double underscore).

    If no suffix is present, then `eq` is returned.
    """
    suffixes = ['eq', 'ne', 'lt', 'le', 'gt', 'ge']
    for suffix in suffixes:
        if s.endswith(suffix):
            return suffix
    return 'eq'
