Writing data from a Python List to CSV row-wise

Comma Separated Values (CSV) files a type of a plain text document in which tabular information is structured using a particular format.  A CSV file is a bounded text format which uses a comma to separate values. The most common method to write data from a list to CSV file is the writerow() method of writer and DictWriter class. Example 1: Creating a CSV file and writing data row-wise into it using writer class. 

Python3

# Importing library
import csv

# data to be written row-wise in csv file
data = [['Geeks'], [4], ['geeks !']]

# opening the csv file in 'w+' mode
file = open('g4g.csv', 'w+', newline ='')

# writing the data into the file
with file:
    write = csv.writer(file)
    write.writerows(data)

Output: Example 2: Writing data row-wise into an existing CSV file using DictWriter class. 

Python3

# importing library
import csv

# opening the csv file in 'w' mode
file = open('g4g.csv', 'w', newline ='')

with file:
    # identifying header
    header = ['Organization', 'Established', 'CEO']
    writer = csv.DictWriter(file, fieldnames = header)

    # writing data row-wise into the csv file
    writer.writeheader()
    writer.writerow({'Organization' : 'Google',
                     'Established': '1998',
                     'CEO': 'Sundar Pichai'})
    writer.writerow({'Organization' : 'Microsoft',
                     'Established': '1975',
                     'CEO': 'Satya Nadella'})
    writer.writerow({'Organization' : 'Nokia',
                     'Established': '1865',
                     'CEO': 'Rajeev Suri'})

Output: Example 3: Appending data row-wise into an existing CSV file using writer class. 

Python3

# Importing library
import csv

# data to be written row-wise in csv file
data = [['Geeks for Geeks', '2008', 'Sandeep Jain'],
        ['HackerRank', '2009', 'Vivek Ravisankar']]

# opening the csv file in 'a+' mode
file = open('g4g.csv', 'a+', newline ='')

# writing the data into the file
with file:
    write = csv.writer(file)
    write.writerows(data)

Output: