with open("example.txt", "a") as myfile:
    print("Hello students!! Here is a little program i made to test your knowledge on \ndifferent topics such as Maths, History and Geography :)")
    Name = input("Please Enter your Name")
    Age = input("Please Enter your Age")
    YearGroup = input("Please enter your Year Group")
    first_three_letters = Name[:3]
    username = "".join((first_three_letters,Age))
    myfile.write(username)
    myfile.close()

with open("example2.txt", "a") as myfile:
    password = input("Please create a password")
    myfile.write(password)
    myfile.close()