import pandas as pd


def apply_trending_flag(
    df: pd.DataFrame,
    flag_name: str,
    is_trending_lambda,
    reference_column: str | None,
) -> None:
    flag_column = f'{flag_name}_flag'
    lift_column = f'{flag_name}_lift'
    df[flag_column] = df.apply(lambda row: 1 if is_trending_lambda(row) else 0, axis=1)
    df[lift_column] = df[reference_column] if reference_column else 0.0


def apply_trending_flags(df: pd.DataFrame, trending_flags: dict) -> None:
    for flag_name, value in trending_flags.items():
        apply_trending_flag(
            df=df,
            flag_name=flag_name,
            is_trending_lambda=value['is_trending_lambda'],
            reference_column=value['lift_feature'],
        )