def _create_cross_series_feature(df, group, col, func):
    """
    Creates aggregate functions for statistics within a cluster
    df: pandas df
    group: str
        Column name used for groupby
    col: str
        Column name on which functions should be applied
    func: list
        list of pandas-compatible .transform(func) of aggregation functions
        
    Returns:
    --------
    pandas df
    """
    
    col_name = col + '_' + func
    df.loc[:, col_name] = df.groupby(group)[col].transform(func)
    return df