Python - Error código Pirámide (*) Ayuda!

def christmastree(n):

    # your code goes here

  for i in range(1, n + 1):

    for j in range(n - i):

      print(" ", end="")

    for j in range(2 * i - 1):

      print("*", end="")

    print()

print(christmastree(5))

def christmastree(n):

    # your code goes here

  for i in range(1, n + 1):

    for j in range(n - i):

      print(" ", end="")

    for j in range(2 * i - 1):

      print("*", end="")

    print()

christmastree(5)

entonces mi pregunta es, debo modificar el codigo???

agregar un return? para que no me ocurra lo anterior

def christmastree(n):

    arbol=""

    for i in range(1, n + 1):

        for j in range(n - i):

            arbol+=" "

        for j in range(2 * i - 1):

            arbol+="*"

        arbol+='\n'

    return arbol

print(christmastree(5))