[SOLVED] Python writes extra blank line to the file

Python writes extra blank line to the file

The following code adds an extra blank line ("\r") to every write, whereas it is supposed to just write one ("\r\n") at the end of every write. I have no idea why.

import os

with open("output", "w", encoding="utf-8") as f:
    for i in range(10):
        f.write(str(i) + os.linesep)

It writes to the file: "0\r\r\n1\r\r\n2...9\r\r\n". I am using Python 3.9.16 on Windows. Am I missing something here?

Edit: I tested without encoding="utf-8" as well, and still the same issue happens.

Solution

You don't need to use os.linesep directly. Opening a file for writing in text mode already does newline translation unless you specify a newline setting that turns it off.

In fact, the os.linesep docs specifically warn you not to do this:

Do not use os.linesep as a line terminator when writing files opened in text mode (the default); use a single '\n' instead, on all platforms.