How to read and write csv files in python.md

How read and write csv files in python

CSV files, which are commonly used for data exports, can easily be read or created using the python standard library.

Example: reading values from a csv file

The following program reads the contents of a csv file containing strings separated by commas on multiple lines.

import csv
with open('eggs.csv') as csvfile:
    spamreader = csv.reader(csvfile)
    for row in spamreader:
        print(', '.join(row))

Output:

Spam, Spam, Spam, Spam, Spam, Baked Beans
Spam, Lovely Spam, Wonderful Spam

Example: creating a csv file from a 2D list

The following program creates a csv file from strings in a two-dimensional list.

import csv
output_list = [
    ['Spam', 'Spam', 'Spam', 'Spam', 'Spam', 'Baked Beans'],
    ['Spam', 'Lovely Spam', 'Wonderful Spam']
]
with open('eggs.csv', 'w') as csvfile:
    spamwriter = csv.writer(csvfile)
    for row in output_list:
        spamwriter.writerow(row)

When you run the program, a csv file will be created, containing the values from output_list. Each sublist corresponds to one line.