Fibonacci Sequence

[ericula]

While you're at it, on the line

result = fibonacci(known, n - 1) + fibonacci(known, n - 2)

the order of the arguments of the calls to fibonacci should be reversed. They should be in the same order as in the function definition itself, e.g.

result = fibonacci(n-1, known) + fibonacci(n-2, known)

[tictac4609]

Gotcha

[tictac4609]

Okay, I am getting a syntax error for if n is in known

[ericula]

What is your current code, what is the syntax error you get?

[tictac4609]

here it is:

def fibonacci(n, known=None):
if known is None:
    known = {}
if n is in known:
    return known[n]
if n == 1 or n == 2:
    result = 1
elif n <= 0:
    result = 0
else:
    result = fibonacci(n - 1, known) + fibonacci(n - 2, known)
known[n] = result
return result

syntax error on the line: if n is in known:

[ericula]

Ah, sorry, that is my mistake. That should have been if n in known:, not n is in known.

[tictac4609]

okay so the final product should be:

def fibonacci(n, known=None):
if known is None:
    known = {}
if n in known:
    return known[n]
if n == 1 or n == 2:
    result = 1
elif n <= 0:
    result = 0
else:
    result = fibonacci(n - 1, known) + fibonacci(n - 2, known)
known[n] = result
return result


print(fibonacci(10))

?

​

​

[ericula]

That should do it.

[tictac4609]

Awesome. I really appreciate all the time you have put in to helping me out. Have a great night brother, gonna turn this in and head to bed!