#Export list to text file python how to
#Export list to text file python code

Notice that the separation character # doesn’t appear after the last element. I have used the # character in this example because in this way it’s easier to see how the # is used to separate elements in the list. Maybe it’s easier to show it in the Python shell 🙂 > months = The string join method joins the elements of a sequence into a single string where every element is separated from another by the string the join method is applied to. I wonder if I can replace the for loop with a single line that uses the string join() method. Syntax to Write a List to File Using the String Join Method With open('months.txt', 'w') as output_file:Įxecute it and confirm that every element in the list is written to the file as expected.

#Export list to text file python code

Here is how our Python code becomes… months = The “with open” statement creates a context manager and this syntax automatically closes the file object when you don’t need it anymore. Instead of remembering to close the file object after the end of the for loop, we can use the Python with open statement. Method to Write a List to a File Using the With Open Statement The Python interpreter tries to open the file in read mode but considering that the file doesn’t exist we get back the “No such file or directory” error.

Python 3 Traceback (most recent call last):įile 'write_list_to_file.py', line 3, in įileNotFoundError: No such file or directory: 'months.txt' IOError: No such file or directory: 'months.txt' Python 2 Traceback (most recent call last): If you delete the file months.txt and rerun the program you get a different error. If you are using Python 2 you will see the following error: IOError: File not open for writing Without passing the second parameter to the open() function we have opened the file in read mode. The error tells us that the file has not been opened for writing. Here is the error we get when we run our code with Python 3 if we don’t delete the months.txt file created in the previous example: $ python write_list_to_file.pyįile 'write_list_to_file.py', line 6, in Notice that we have removed the second argument passed to the open() function that was telling the function to open the file in write mode. With the following… output_file = open('months.txt') Replace the following line in your Python code: output_file = open('months.txt', 'w') I want to see what happens if we don’t open the file in write mode. The output looks a lot better now: $ cat months.txtĪpril What Error Do You See When Writing a List into a File Opened in Read Mode? It looks like we are missing newline characters at the end of each line, let’s add a newline to the write method in each iteration of the for loop: output_file = open('months.txt', 'w') Now, let’s have a look at what the content of the file looks like using the cat command (or any text editor). Then, close the file object once you have written all the elements of the list to it. We write to the text file using the write method of the file object. Each iteration of the for loop writes an element of the list months to the file.

Using the Python open() built-in function we open a new file in write mode. In the first Python program, we will open a file object in write mode and then use a for loop to write each element in our data structure to the file: output_file = open('months.txt', 'w') Let’s have a look at how you can take the list of strings below and store each string in a text file using Python. This might be required, for example, if you store data in a file every time you run your application and that data can be available for later use the next time you run your application. Imagine you are building an application that has to persist a list of items after its execution. Let’s have a look at a few examples! Python Program to Write a List to a File in Python Using a Loop There are many scenarios in which writing the items of a list to a file can turn out useful. The file object needs to be opened in write mode. Then use a file object to write every element of the list to the file as part of each loop iteration.

#Export list to text file python how to

This tutorial will show you how to do that in multiple ways.Ī common approach to write list elements to a file using Python is to first iterate through the elements of the list using a for loop. Knowing how to write the elements of a list to a file in Python can be handy.