Python save str to file

Write String to Text File in Python

In this Python tutorial, you will learn how to write a string value to a text file, using write() method of file class.

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

1. Write string to new text file

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

Python Program

#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()

Reference tutorials for the above program

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.

Python Program

#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)

2. Write string value 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.

Python Program

#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.

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How to Write String to Text File in Python?

Now you can save or write string to text a file in persistent data storage using Python.

To write string to a Text File, follow these sequence of steps:

1. Open file in write mode using open() function.
2. Write string to the file using write() method.
3. Close the file using close() method.

Examples

1. Write string to text file

In the following example, we will take a string constant and write the string to a text file by following the above said sequence of steps.

Python Program

text_file = open("sample.txt", "w") n = text_file.write('Welcome to pythonexamples.org') text_file.close()

The write() method returns the number of characters written to the text file.

Note that this kind of writing to text file, overwrites the data, if the file is already present. If the file is not present, it creates a new file and then writes the string to the file.

2. Write string to text file in text mode

A file can be opened in two modes: the first one is text mode and the second one is binary mode. By default a file is opened in text mode. However, you can explicitly specify the mode.

In the following example, we will open the file in text mode by appending “t” to the mode and write the string to a text file by following the sequence of steps mentioned at the start of this tutorial.

Python Program

text_file = open("sample.txt", "wt") n = text_file.write('Welcome to pythonexamples.org') text_file.close()

Writing other than String to Text File

If you would like to write any Python object other than string or a bytes object to a file, using write() method, you should first convert that Python object to a string or bytes object.

Summary

In this tutorial of Python Examples, we learned how to write a string to a text file, with the help of example programs.

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Write String to a .csv File in Python

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:

1. Import the csv module.
2. 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.
3. Create a CSV writer object using csv.writer() .
4. Write the strings to the file using the writerow() method.
5. Close the file using the close() method.

Let’s write some sentences to a new CSV file in Python called usa.csv .

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 ‘a’ .

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 with statement:

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:

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.

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How to Write a String to a Text File using Python

Steps to Write a String to a Text File using Python

Step 1: Specify the path for the text file

To begin, specify the path where the text file will be created.

For example, let’s suppose that a text file will be created under the following path:

Step 2: Write a string to a text file using Python

Next, write your string to the text file using this template:

text_file = open(r'path where the text file will be created\file name.txt', 'w') my_string = 'type your string here' text_file.write(my_string) text_file.close()

• The path where the text file will be created is: C:\Users\Ron\Desktop\Test
• The file name (with the txt file extension) is: Example.txt
• my_string contains the following text: ‘This is a Test‘

So the full Python code would look as follows (don’t forget to place ‘r‘ before your path name to avoid any errors in the path):

text_file = open(r'C:\Users\Ron\Desktop\Test\Example.txt', 'w') my_string = 'This is a Test' text_file.write(my_string) text_file.close()

Once you run the code (adjusted to your path), you’ll then see the new text file in your specified location.

If you open the text file, you’ll see the actual string:

Overwrite the String

What if you want to overwrite the original string with a new value?

For instance, what if you want to change the string to the following value:

‘This is a NEW Test‘

In that case, simply edit the text as follows:

my_string = 'This is a NEW Test'

So the new Python code would look like this:

text_file = open(r'C:\Users\Ron\Desktop\Test\Example.txt', 'w') my_string = 'This is a NEW Test' text_file.write(my_string) text_file.close()

Run the code, and you’ll see the new string:

List of Strings

Say that you want to display a list of strings in your text file.

Here is an example of a list with strings:

my_list = ['This is a Test', 'This is ALSO a Test', 'This is a FINAL Test']

In that case, you may use a for loop to display your list of strings in the text file:

text_file = open(r'C:\Users\Ron\Desktop\Test\Example.txt', 'w') my_list = ['This is a Test', 'This is ALSO a Test', 'This is a FINAL Test'] for i in my_list: text_file.write(i + '\n') text_file.close()

You’ll now see that each of the strings is presented in a new line:

Dealing with Integers

If you try to print integers into the text file, you’ll get the following error:

write() argument must be str, not int

You may then choose to convert the integers to strings.

For example, let’s suppose that you have two integers (3 and 5), and you want to present the sum of those integers in the text file.

In that case, you may apply the following syntax to achieve the above goal (notice that str() was used to convert the integers to strings):

text_file = open(r'C:\Users\Ron\Desktop\Test\Example.txt', 'w') sum_values = 3 + 5 text_file.write(str(sum_values)) text_file.close()

You’ll then get the sum of 8 in the text file:

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