[python] Python write line by line to a text file

I am trying to output the result from a Python script to a text file where each output should be saved to a line.

f1=open('./output.txt', 'a')
f1.write(content + "\n")

When I open output.txt with the regular notepad the results look like this:

color amber color aqua color analysis color app color adobe color alive app

However, when I open the file with notepad++ it looks fine and each word is saved on a line.

How can make the script save the result line-by-line so it would show the same on the regular notepad?

You may want to look into os dependent line separators, e.g.:

import os

with open('./output.txt', 'a') as f1:
    f1.write(content + os.linesep)