def get_marks(df, subjects, terms=[1, 2, 3, 4, 5, 6, 7, 8]):
    """
    Returns a data frame with marks for given subjects and terms for given schools

    Parameters
        ----------
        subjects : list of subjects ["History","Sinhala","English"]
        terms : list of terms from 1 to 9 [1,2]
                if not specified return marks for all the terms.
    """

    columns = []

    for subject in subjects:

        for term in terms:
            columns.append((subject + "_" + str(term)).rstrip())

    df = df[columns]

    return df