def create_csv(filename, csv_data, mode='w'):
    """
    Create a CSV file with the given data and store it in the
    file with the given name.

    :param filename: name of the file to store the data in
    :pram csv_data: the data to be stored in the file
    :param mode: the mode in which we have to open the file. It can
                 be 'w', 'a', etc. Default is 'w'
    """
    with open(filename, mode) as f:
        csv_data.replace('_', '\\_')
        f.write(csv_data)
