Welcome folks today in this post we will be talking about how to write csv files using csvwriter class and dictwriter class. This will be a full project for beginners in python 3. All the source code of examples are shown below.

Installation

In order to get started you should have installed python on your system and also we must need a module called as csv for interacting with csv files in python. You can install that module using pip command as follows

pip install csv

Methods Used

Now to Write CSV Files in Python we will be using two classes namely called csvwriter and dictwriter in csv module.

First we will discuss csvwriter class so make a app.py file and write code in that

In this csvwriter class we have two methods

writerow This is a method used to write a single row to a csv file at a time

writerows This method can be used to write multiple rows to a csv file at a time

app.py

# Python program to demonstrate 
# writing to CSV 


import csv 
    
# field names 
fields = ['Name', 'Branch', 'Year', 'CGPA'] 
    
# data rows of csv file 
rows = [ ['Nikhil', 'COE', '2', '9.0'], 
        ['Sanchit', 'COE', '2', '9.1'], 
        ['Aditya', 'IT', '2', '9.3'], 
        ['Sagar', 'SE', '1', '9.5'], 
        ['Prateek', 'MCE', '3', '7.8'], 
        ['Sahil', 'EP', '2', '9.1']] 
    
# name of csv file 
filename = "university_records.csv"
    
# writing to csv file 
with open(filename, 'w') as csvfile: 
    # creating a csv writer object 
    csvwriter = csv.writer(csvfile) 
        
    # writing the fields 
    csvwriter.writerow(fields) 
        
    # writing the data rows 
    csvwriter.writerows(rows)

Now we will talk about the second class DictWriter class to write csv files

Inside this class we have two methods

writeheader This method is used to write the header of the csv files namely the columns

writerows This method writes all the rows at once except it doesn’t write keys only values

app.py

# importing the csv module 
import csv 
    
# my data rows as dictionary objects 
mydict =[{'branch': 'COE', 'cgpa': '9.0', 'name': 'Nikhil', 'year': '2'}, 
        {'branch': 'COE', 'cgpa': '9.1', 'name': 'Sanchit', 'year': '2'}, 
        {'branch': 'IT', 'cgpa': '9.3', 'name': 'Aditya', 'year': '2'}, 
        {'branch': 'SE', 'cgpa': '9.5', 'name': 'Sagar', 'year': '1'}, 
        {'branch': 'MCE', 'cgpa': '7.8', 'name': 'Prateek', 'year': '3'}, 
        {'branch': 'EP', 'cgpa': '9.1', 'name': 'Sahil', 'year': '2'}] 
    
# field names 
fields = ['name', 'branch', 'year', 'cgpa'] 
    
# name of csv file 
filename = "university_records.csv"
    
# writing to csv file 
with open(filename, 'w') as csvfile: 
    # creating a csv dict writer object 
    writer = csv.DictWriter(csvfile, fieldnames = fields) 
        
    # writing headers (field names) 
    writer.writeheader() 
        
    # writing data rows 
    writer.writerows(mydict)