def normalize_df(levels_df):
    """
    Normalize the passed dataframe

    Args:
        levels_df: pandas dataframe to be normalized

    Returns:
        Normalized dataframe
    """

    result = levels_df.copy()

    # Normalize each column one by one
    for feature_name in levels_df.columns:
        max_value = levels_df[feature_name].max()
        min_value = levels_df[feature_name].min()
        result[feature_name] = (levels_df[feature_name] - min_value) / (max_value - min_value)

    return result