99-bottles.py

output = ""
bottles = 99

def bottle_str(bottles):
    if bottles == 0:
        return "No bottles"
    elif bottles == 1:
        return "1 bottle"
    else:
        return f"{bottles} bottles"

while bottles > 0:
    output += f"{bottle_str(bottles)} of beer on the wall\n"
    output += f"{bottle_str(bottles)} of beer\n"
    output += f"Take one down, pass it around\n"
    bottles = bottles - 1
    output += f"{bottle_str(bottles)} of beer on the wall\n\n"

f = open("99-bottles.txt", "w")
f.write(output)