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 libraryimport csv# data to be written row-wise in csv filedata = [['Geeks'], [4], ['Lazyroar !']]# opening the csv file in 'w+' modefile = open('g4g.csv', 'w+', newline ='')# writing the data into the filewith 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 libraryimport csv# opening the csv file in 'w' modefile = 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 libraryimport csv# data to be written row-wise in csv filedata = [['Geeks for Geeks', '2008', 'Sandeep Jain'], ['HackerRank', '2009', 'Vivek Ravisankar']]# opening the csv file in 'a+' modefile = open('g4g.csv', 'a+', newline ='')# writing the data into the filewith file: write = csv.writer(file) write.writerows(data) |
Output: 
