import os

with open("../demo.txt", 'w') as fout:
    fout.write("one" + "\n")
    fout.write("one two" + "\n")
    fout.write("one two three" + "\n")
    fout.write("one two three four" + "\n")
    fout.write("one two three four five" + "\n")
    fout.write("one two three four five six" + "\n")
    fout.write("one two three four five six seven" + "\n")
