import csv


def read_all_reviews(filepath):
    """
    Read CSV file that contains all reviews into a string
    Returns:
        text (string)
    """
    with open(filepath, 'r', encoding='utf-8') as f:
        reader = csv.reader(f)
        L = []
        for row in reader:
            L += row
    f.close()
    text = ','.join(L)
    return text