a = open("1.txt","r+")
b = open("2.txt","r+")
for i in a.readlines():
    io=str(i)+"$"
    e = b.writelines(io)

a.close()
b.close()

io = i.rstrip() + "$" + 'n'

with open("1.txt", "r") as inFile:
    with open("2.txt", "w") as outFile:
        for line in inFile:
            outFile.write(line.strip() + "$n")

a = open("1.txt","r+")
b = open("2.txt","r+")
for i in a.readlines():
    io=i[:-1] + "$n"
    e = b.write(io)

a.close()
b.close()