def get_insight(df):
    """
    Get insight from a youtube_history dataframe transformed by transform()

    Parameters
    ----------
    df : DataFrame
        A youtube_history dataframe transformed by transform()

    Returns
    -------
    df_info : dictionary
        Contains informations about a specific youtube_history dataframe transformed by transform()

    """
    df_info = {}
    df_info['period'] = {
    "from" : min(df['year']),
    "to" : max(df['year'])
    }
    df_info['nbr_watched'] = df.shape[0]
    df_info['first'] = df.iloc[-1, df.columns.tolist().index("titleUrl")]
    df_info['last'] = df.iloc[0, df.columns.tolist().index("titleUrl")]
    return df_info