Add new column in a csv within a loop with python

Question

I write data from a loop to a csv-file.

Expected outcome: Every iteration should write data in a new column.

Actually, it overwrites the data of the last iteration. How could I add a new column for every iteration?

def keywordsToCsv(filename, single_phrases):

    path = 'keywords/keywords.csv'

    with open(path, 'w', encoding='utf-8') as csvfile:
        filewriter = csv.writer(csvfile, delimiter=',', quotechar='|', quoting=csv.QUOTE_MINIMAL)
        filewriter.writerow([filename])
        for phrase in single_phrases:
            filewriter.writerow([phrase])

Answer 1

There's no need to write a new column to the CSV file for each iteration. Instead, you can delay writing the columns and keep appending the output columns to a list until the loop finishes, at which point you can write all the columns as one row together.