What's the proper syntax for writing this to a file?

Question

def guessingTime(answer, username):
    vdfile = open("victorydefeat.txt", "a")
    now = time.asctime(time.localtime(time.time()))
    victory = username + "successfully guess" + answer + "on" + now
    defeat = username + "was unable to guess" + answer + "on" + now
    print("That's 20! Time to guess.")
    guess = input("Is it a(n): ")
    if guess.lower() == answer:
        print("You got it! Congratulations!")
        vdfile.write(victory)
        vdfile.write("\n")
    else:
        print("Sorry, but the answer was", answer)
        vdfile.write(now)
        vdfile.write("\n")
    vdfile.close()

def main():
    print("Welcome to 20 questions! The game where I (your humble program) will think of an object and you (the beloved user) will try to guess it!")
    username = print(input(("Now, before we begin, I'd like to know your name (for recording purposes): ")))
    infile1, infile2, answer = getAnswer()
    #startAsking(infile1, infile2)
    guessingTime(answer, username)

main()

The error message is "unsupported operand type(s) for += 'NoneType' and 'str'" for the "victory =" line. I want to write: " successfully guessed on ". What do I do?

Answer 1

print() does not return a value. Because of this username is being set to None.

input() will print the string it is passed and return the entered text. You just want the following:

username = input("Now, before we begin, I'd like to know your name (for recording purposes): ")

Answer 2

You can just use time.asctime(), it is the local time by default. Also, string formatting is your friend:

"{0} guessed {1} on {2}".format(username, answer, time.asctime())

However one of your arguments username or answer is None (as unholysampler explains) which is why you get that specific error.