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 ], [ 'Lazyroar !' ]] # 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: