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Write a list to a file in Python with each item on a new line

Write a list to a file in Python with each item on a new line

David Y.

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The ProblemJump To Solution

I have a list that looks like this:

Click to Copy
fruits = ["Apples", "Oranges", "Pears", "Bananas", "Pineapples"]

How can I write the contents of this list to a file such that each item appears on its own line? In other words, I want a file that looks like this:

Click to Copy
Apples
Oranges
Pears
Bananas
Pineapples

The Solution

We can do this using Python’s str.join method, which takes a list and returns a string containing each list item separated by the string it was called on. Here’s how we might use it to write a list to a file:

Click to Copy
fruits = ["Apples", "Oranges", "Pears", "Bananas", "Pineapples"]

with open("fruits.txt", mode="w") as fruitfile:
    fruitfile.write("\n".join(fruits) + "\n")

fruits.txt will contain the following lines:

Click to Copy
Apples
Oranges
Pears
Bananas
Pineapples

We’ve added a new line at the end of the file to respect POSIX conventions, which stipulate that all lines should end with newline characters. This will also make it easier to append additional lines to the file in the future.

join will throw a TypeError if it comes across items in the list that aren’t strings. We can avoid this error by converting all elements of our list to strings using a list comprehension:

Click to Copy
numbers = [1, 2, 3, 4, 5]

with open("fruits.txt", mode="w") as numberfile:
    numberfile.write("\n".join(str(n) for n in numbers) + "\n")
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