🔒 Beginner confusion

[void sentinel]

Why is the result printed as only [0]? Isn’t this code supposed to “return” a sequence of the Fibonacci until it is greater than n, or am I misunderstanding the return function too

[hidden jacinth]

@void sentinel

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[near aurora]

You didn't say to print(f100)
You only have print(fib(0)) so you only see what that print printed

[tough wraith]

!indent

[hidden jacinth]

Indentation

Indentation is leading whitespace (spaces and tabs) at the beginning of a line of code. In the case of Python, they are used to determine the grouping of statements.

Spaces should be preferred over tabs. To be clear, this is in reference to the character itself, not the keys on a keyboard. Your editor/IDE should be configured to insert spaces when the TAB key is pressed. The amount of spaces should be a multiple of 4, except optionally in the case of continuation lines.

Example

def foo():
    bar = 'baz'  # indented one level
    if bar == 'baz':
        print('ham')  # indented two levels
    return bar  # indented one level

The first line is not indented. The next two lines are indented to be inside of the function definition. They will only run when the function is called. The fourth line is indented to be inside the if statement, and will only run if the if statement evaluates to True. The fifth and last line is like the 2nd and 3rd and will always run when the function is called. It effectively closes the if statement above as no more lines can be inside the if statement below that line.

Indentation is used after:
1. Compound statements (eg. if, while, for, try, with, def, class, and their counterparts)
2. Continuation lines

More Info
1. Indentation style guide
2. Tabs or Spaces?
3. Official docs on indentation

[tough wraith]

you return the result on the first iteration

also well, your 2 screenshot is not continuous

[near aurora]

This isn't repl to print automatically everything that had a value. (the line saying just f100)
File script will only print what you explicitly tell it to print, hence only print(fib(0)) shows up

And after you fix f100 to be print(f100), that's when you'll get the exact same result and indent will matter (what Noping tells you)

[tough wraith]

A trace for you, if it is helpful

[void sentinel]

Is this an incorrect fix?

I know it feels like talking to a wall lol

[fluid scarab]

!d yield

[hidden jacinth]

yield

7.7. The yield statement

yield_stmt ::= yield_expression

A yield statement is semantically equivalent to a yield expression. The yield statement can be used to omit the parentheses that would otherwise be required in the equivalent yield expression statement. For example, the yield statements...

[fluid scarab]

i think this might be the one you want rather then return

oh, i see now that you are doing append and returning the list, forget what i just said

but if you are going to do return, you want to do it after the loop is done

so, outside of the loop

[void sentinel]

Does return break the loop so I only get the result of 0?

[red jungle]

the moment any function hits the return keyword, it immediately stops and returns the requested value. Your while loop completely stops during teh first loop, therefore you only append a single value of 0 to your list and return that

[void sentinel]

Ohhh okay

[fluid scarab]

yes, return returns exits the funciton

all you would need to do is unindent the return statement one position so that it is on the same level as the while keyword

[void sentinel]

When I change the value of a, b = 0, 1 to like = 3, 5 is there a reason it doesn’t return 3 and only 0 again?

[red jungle]

did you save the file before running it?

[fluid scarab]

yield that i mentioned before would have made your function a generator, which returns data for each time it hits the yield keyword and doesn't stop until the function ends in some other way

[red jungle]

just keep in mind that using yield instead of return here will not achieve the behaviour that the docstring mentions

[void sentinel]

Ohh okay

[void sentinel]

I saved and it worked my bad

Or refreshed

[red jungle]

!e

def fib2(n):
    result = []
    a, b = 3, 5
    while a < n:
        result.append(a)
        a,b = b,a+b
        return result
print(fib2(100))

[hidden jacinth]

:white_check_mark: Your 3.12 eval job has completed with return code 0.

[3]

[red jungle]

yeah that's what I would expect 🙂

one change to that code will give you the list you're after

[void sentinel]

Thank you

[fluid scarab]

just a demo of how yield would work in this situation

!e

def fib(n):
    a, b = 1, 1
    while a < n:
        yield a
        a, b = b, a + b
       
print(list(fib(100)))

[hidden jacinth]

:white_check_mark: Your 3.12 eval job has completed with return code 0.

[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]

[lime nest]

Btw is it a good way to define a fib function?
I was told that fib should be best defined the calling the function in the defination , using fib(n) , if n > 2 , return fib(n-1) + fib(n-2)

[fluid scarab]

that looks like functional programming where you use recursion a lot more as variables are immutable in strictly functional languages

it would use up a lot more resources, especially in python

also, it's slower if not using memoization (caching of function return values dependent on the values of function arguments)

my preference in python would be to use a loop similar to the implementation you went with

[hidden jacinth]

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