import csv


def read_csv(filename, separator=',', quote='"'):
    """
    Inputs:
        filename    - name of CSV file
        separator   - character that separates fields
        quote       - character used to optionally quote fields
    Output:
        Returns a list. Each item corresponds to a row
        in the CSV file where the transaction was completed.
    """
    list_out = []
    with open(filename, newline='') as csv_in:
        csv_reader = csv.DictReader(csv_in, delimiter=separator, quotechar=quote)
        for row in csv_reader:
            if row['Sales state'] == 'completed':
                details = row['Details Summary'].replace('\n','')
                list_out.append(details)
    return list_out