Generate Strata instance automatically

    Parameters
    ----------
    scores : array-like, shape=(n_items,)
        ordered array of scores which quantify the classifier confidence for
        the items in the pool. High scores indicate a high confidence that
        the true label is a "1" (and vice versa for label "0").

    **kwargs :
        optional keyword arguments. May include 'stratification_method',
        'stratification_n_strata', 'stratification_n_bins'.

    Returns
    -------
    Strata instance

def auto_stratify(scores, **kwargs):
    """Generate Strata instance automatically

    Parameters
    ----------
    scores : array-like, shape=(n_items,)
        ordered array of scores which quantify the classifier confidence for
        the items in the pool. High scores indicate a high confidence that
        the true label is a "1" (and vice versa for label "0").

    **kwargs :
        optional keyword arguments. May include 'stratification_method',
        'stratification_n_strata', 'stratification_n_bins'.

    Returns
    -------
    Strata instance
    """
    if 'stratification_method' in kwargs:
        method = kwargs['stratification_method']
    else:
        method = 'cum_sqrt_F'
    if 'stratification_n_strata' in kwargs:
        n_strata = kwargs['stratification_n_strata']
    else:
        n_strata = 'auto'
    if 'stratification_n_bins' in kwargs:
        n_bins = kwargs['stratification_n_bins']
        strata = stratify_by_scores(scores, n_strata, method = method, \
                                         n_bins = n_bins)
    else:
        strata = stratify_by_scores(scores, n_strata, method = method)
    return strata