In this tutorial, we will learn how to write strings to a .csv file in Python. Comma-separated values (CSV) files are a common file format for transferring and storing data. Python provides a built-in module called
csv that allows you to easily work with CSV files.
Write Strings to a New CSV File in Python
To write strings to a new CSV file, you can use the
csv module. Here’s how you can do it:
- Import the
- Open the file in write mode using the
open()function. Use the mode
'w'. This will create a new file if it doesn’t exist or truncate the file if it exists.
- Create a CSV writer object using
- Write the strings to the file using the
- Close the file using the
Let’s write some sentences to a new CSV file in Python called
import csv # Open the file in write mode file = open('usa.csv', 'w', newline='') # Create a CSV writer object csv_writer = csv.writer(file) # Write strings to the file csv_writer.writerow(["The United States of America is a country consisting of 50 states."]) csv_writer.writerow(["The capital city is Washington, D.C., and the largest city is New York City."]) # Close the file file.close()
Now, when you open the file, you can see those sentences have been written to the usa.csv file.
Write Strings to an Existing CSV File in Python
If you want to add strings to an existing CSV file, you need to open the file in append mode by using the mode
Here’s how you can append strings to an existing CSV file in Python:
# Open the file in append mode file = open('usa.csv', 'a', newline='') # Create a CSV writer object csv_writer = csv.writer(file) # Write strings to the file csv_writer.writerow(["The United States is known as the land of opportunities."]) csv_writer.writerow(["English is the primary language spoken in the United States."]) # Close the file file.close()
Using ‘with’ statement for file handling
It’s good practice to use the
with statement when dealing with file objects. This has the advantage that the file is properly closed after its suite finishes executing.
Here’s how you can write to a CSV file using the
import csv # Using with statement to write to a new file with open('usa_new.csv', 'w', newline='') as file: csv_writer = csv.writer(file) csv_writer.writerow(["The currency of the United States is the US Dollar."]) csv_writer.writerow(["The US has a rich history with a significant impact on global politics and economy."]) # Using with statement to append to an existing file with open('usa_new.csv', 'a', newline='') as file: csv_writer = csv.writer(file) csv_writer.writerow(["The Statue of Liberty is one of the most iconic landmarks in the US."]) csv_writer.writerow(["The United States has some of the best universities in the world such as MIT and Harvard."])
In this tutorial, I have explained to you, how to write strings to a .csv file in Python. We have learned the process of creating a new CSV file and appending data to an existing one. By utilizing Python’s built-in
csv module, we have seen how simple and efficient it can be to handle CSV files.
Other Python tutorials you may like:
- Convert Epoch to Datetime in Python
- Python Read Excel File and Write to Excel File in Python
- Python Pandas Write to Excel
I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.