def compute_mean_median(all_methods_df):
    """
    Computes the mean values and the median values for each column of the Pandas.DataFrame grouped by the methods.

    Parameters
    ----------
    all_methods_df : Pandas.DataFrame

    Returns
    -------
        list
        - means: Pandas.DataFrame containing the mean values for each column of the Pandas.DataFrame grouped by the methods
        - medians: Pandas.DataFrame containing the meadian values for each column of the Pandas.DataFrame grouped by the methods
    """

    grouped = all_methods_df.groupby("method")
    means = round(grouped.mean(), 4)
    medians = round(grouped.median(), 4)
    return [means, medians]