Save List to File with Newlines in Python

General Discussions
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#1

How to Save a List to a File in Python with Newlines? I need to save a list to a file in Python, but the writelines() method does not automatically insert newline characters. How can I write the list to a file so that each element appears on a new line?

For example, I currently have to use:

f.writelines([f"{line}\n" for line in lines])

Is there a more efficient or standard way to achieve this?

#2

I’ve worked with file handling in Python a lot, so let me break it down for you. One effective way to save a list to a file in Python with newlines is to use the writelines() method, just as you mentioned. However, instead of creating an intermediate list with newline characters, you can make the code more concise by using a generator expression directly:

with open('file.txt', 'w') as f:
    f.writelines(f"{line}\n" for line in lines)

This approach keeps it efficient because you’re avoiding the extra memory overhead of creating a new list in memory. It’s short, clear, and gets the job done nicely.

#3

Good point from Emma, but I think there’s another way to tackle this. You can achieve the same goal using a for loop with the write() method. This method might appeal to you if you want more control or just prefer its explicitness. Here’s how you can use it to save a list to a file in Python:

with open('file.txt', 'w') as f:
    for line in lines:
        f.write(f"{line}\n")

This method is super clear—you’re explicitly iterating over each element, appending the newline, and writing it to the file. It’s also great if you ever need to add additional formatting logic inside the loop.

#4

Both approaches above are solid, but let me suggest a slightly different route. You can also use Python’s print() function with the file argument. The advantage of this method is that print() automatically appends a newline for you, so you don’t need to include \n manually:

with open('file.txt', 'w') as f:
    for line in lines:
        print(line, file=f)

This is probably the most beginner-friendly way to save a list to a file in Python. It’s clean, readable, and does exactly what you need with minimal fuss. Plus, if you’re already comfortable with print(), there’s no extra learning curve!