Add new data to a text file without overwriting it in python

Question

Right, I'm running a while loop that does some calculations, and, at the end, exports the data to a .txt file. The problem is, rather than appending the data to the end of the file, it seems to overwrite it and create a brand new file instead. How would I make it append to the old file?

Here's my code:

turn = 1
while turn < times:
    dip1 = randint(1,4)
    dip2 = randint(1,4)
    dip = (dip1 + dip2) - 2

    adm1 = randint(1,4)
    adm2 = randint(1,4)
    adm = (adm1 + adm2) - 2

    mil1 = randint(1,4)
    mil2 = randint(1,4)
    mil = (mil1 + mil2) - 2

    with open("Monarchs Output.txt", "w") as text_file:
        print("Monarch{}, adm: {}, dip: {}, mil: {}\n".format(turn, adm, dip, mil), file=text_file)

    turn = turn + 1

Just to note, it runs just fine, all the required imports are at the top of the code.

Answer 1

Open the file before the loop starts. Every time you open the file for writing, it creates a new file (it deletes whatever is in it).

with open("Monarchs Output.txt", "w") as text_file:
    turn = 1
    while turn < times:
        dip1 = randint(1,4)
        dip2 = randint(1,4)
        dip = (dip1 + dip2) - 2

        adm1 = randint(1,4)
        adm2 = randint(1,4)
        adm = (adm1 + adm2) - 2

        mil1 = randint(1,4)
        mil2 = randint(1,4)
        mil = (mil1 + mil2) - 2

        print("Monarch{}, adm: {}, dip: {}, mil: {}\n".format(turn, adm, dip, mil), file=text_file)

        turn = turn + 1

Answer 2

You should use open("Monarchs Output.txt", "a") instead of open("Monarchs Output.txt", "w")
link: https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files