def get_zero_inflated_series(df, ts_settings, cutoff=0.99):
    """
    Identify series where the target is 0.0 in more than x% of the rows

    df: pandas df
    ts_settings: dict
        Parameters of datetime DR project
    cutoff: np.float
        Threshold for removal of zero-inflated series. Retained series must be present in row >= cutoff

    Returns:
    --------
    List of series
    """
    date_col = ts_settings['date_col']
    series_id = ts_settings['series_id']
    target = ts_settings['target']

    df = df.groupby([series_id])[target].apply(lambda x: (x.dropna() == 0).mean())
    series = df[df >= cutoff].index.values

    return series