Fibonacci Python — unexpected additional output “None”, in the end

Question

Hi lovely people, how are you todayyyy 💛💙 😄

🐍I’ve got a specific question:

This code below almost works — i do get the desired output..but i also get an annoying “None”, as an additional output in the end.

And i don’t know how to make it go away.

So my output is:
0
1
1
2
3
None

If I make the “None” go away, SoloLearn will accept it.

And my code is:

num = int(input())

def fibonacci(n):
#complete the recursive function
fibolist = [0, 1]
for i in range(n):
if i>=2:
fibolist.append(fibolist[i-2] + fibolist[i-1])

for el in fibolist:
print(el)

print(fibonacci(num))

🤔Any ideas?

Please do NOT post your solution in this thread — there are many Fibonacci Python threads in SoloLearn already.

This is a specific question, which might help users who have also seen this situation elsewhere.

So why is the “None” there?

Thank you 🙏😊

Answer 1

Because you are trying to print the value returned by function call "fibonacci(num)" even though you aren't returning anything from function , so it prints None .

Answer 2

Christos Nikolis

You are already printing values in loop inside function so don't print function Just call function.

Answer 3

Christos Nikolis Using return actually stops further execution of function and only first value is returned.

You can instead use yield.

num = int(input())

def fibonacci(n):
#complete the recursive function
fibolist = [0, 1]
for i in range(n):
if i>=2:
fibolist.append(fibolist[i-2] + fibolist[i-1])

for el in fibolist:
yield el

for i in fibonacci(num):
print(i)

I never went into how does yield actually works , so i can't explain it either but in case you wanna know here is a good article about it.

https://www.guru99.com/JUMP_LINK__&&__python__&&__JUMP_LINK-yield-return-generator.html#:~:text=Summary%3A-,The%20yield%20keyword%20in%20python%20works%20like%20a%20return%20with,are%20only%20available%20when%20called.

Answer 4

Christos Nikolis Thank you :)

Answer 5

I Am AJ ! — that works, and thank you!

The only issue I have with your solution is that that was SoloLearn’s premade code (i mean the final print), and so for the sake of challenge i didn’t want to change it.

Answer 6

Abhay — thanks a lot!

I have now replaced the print with *return*, at the end of my function:

for el in fibolist:
return(el)
# that was print(el) initially

And the “None” issue is solved — but now my output is just a single 0.

I know i ask somethind beyond my first question, but any idea why I don’t get returned every element (el) from my fibolist?

As part of the challenge, i don’t want to change SoloLearn’s premade code, at the end of the exercise:

print(fibonacci(num))

I understand if you don’t have the time to reply again, but i’d love it if you did! (-:

Answer 7

Abhay — You have earned yourself a new follower 😁I understand that *return* breaks the function.

I will also read your article, and here’s one more from me:

https://stackoverflow.com/questions/34968634/how-to-return-values-without-breaking-the-loop?newreg=706108581a88413eaedf8aface1ccdb7