def drop_duplicate_claims(df):
    """ Drops rows with duplicate values in claim column. Modifies DF in place! """
    len_with_dupes = len(df['claim'])
    df.drop_duplicates(subset='claim', inplace=True)
    len_no_dupes = len(df['claim'])
    print('Dropped {} duplicate rows.'.format(len_with_dupes - len_no_dupes))
    return df