Python – Write String to Text File

To write string to a file in Python, we can call write() function on the text file object and pass the string as argument to this write() function.

In this tutorial, we will learn how to write Python String to a file, with the help of some Python example programs.

Following is the step by step process to write a string to a text file.

  1. Open the text file in write mode using open() function. The function returns a file object.
  2. Call write() function on the file object, and pass the string to write() function as argument.
  3. Once all the writing is done, close the file using close() function.

Examples

Write String to New Text File

The following is an example Python program in its simplest form to write string to a text file.

Example.py

#open text file
text_file = open("D:/data.txt", "w")

#write string to file
text_file.write('Python Tutorial by TutorialKart.')

#close file
text_file.close()

When we run this program, a new file is created named data.txt in D: drive and the string is written to the file. But to programmatically confirm, you can use the value returned by write() function. write() function returns the number of bytes written to the file.

Example.py

#open text file
text_file = open("D:/data.txt", "w")

#write string to file
n = text_file.write('Python Tutorial by TutorialKart.')

#close file
text_file.close()

print(n)

Output

32

Write to an Existing File

If you try to write a string to an existing file, be careful. When you create a file in write mode and call write() function, existing data is lost and new data is written to the file.

For instance, in the previous example, we created a file and written some data to it.

Now we shall run the following example.

Example.py

#open text file
text_file = open("D:/data.txt", "w")

#write string to file
n = text_file.write('Hello World!')

#close file
text_file.close()

The existing file is overwritten by the new content.

Note: If you would like to append data to a file, open file in append mode and then call write() function on the file object.

Conclusion

In this Python Tutorial, we learned how to write a string to a text file.