🔒 for val in list

[brave aspen]

Here's my code:

mylist = [1, 1, 0, 0, 0, 0, 0, 0, 0]
    
def myfunction(mylist):
    for val in mylist:
        if val != 0:
            return False
        else:
            return True
                
print(myfunction(mylist))

What return I'm expecting: True
What it gives me: False

My intentions: I want to check if there are any 0 in my list.
If there is atleast one 0 in my list, return True.

[light stratus]

@brave aspen

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[brittle wadi]

Do you understand what return does?

[brave aspen]

It's supposed to give the result to the function when I'm trying to access said function.

[brittle wadi]

yes, it's the outcome of calling the function

[brave aspen]

Exactly

[brittle wadi]

return is also the end of the function

once you reach a return line in a function, the function does not proceed as it has already found its outcome

[brave aspen]

Yes, I want to end the loop immediately if it checks a 0 in the list.

It saves some time

instead of going through a long list

[brittle wadi]

yes, but you also have your else: return True inside the loop

so right now you're returning True if the first number is not a zero

so it should return True if there is at least one zero?

Forget about code for a second. Imagine I had a bag of 1s and 0s

I ask you if there's any 0s in the bag

how would you check?

[brave aspen]

yes

[brave aspen]

I iterate it

and if there's the first 0 I see, I close the bag

I ignore all the 1s I get

[pale swallow]

Except as it stands your function immediately returns False when encountering something a 1 it should ignore

[brave aspen]

Damn it

I see it, yet what alternative is there?

ok I could do a sum check

but... if I have a list of 100 items that's gonna take a while

[brittle wadi]

yes, but when will you know that there are no zeroes?

[pale swallow]

You only stop the loop when finding a zero. Ignore doing anything for any other case

[brave aspen]

yeah, trying to find an algorithm to see if there's no more 0 is gonna be clunky

[brittle wadi]

Again, forget about code for a second

[brave aspen]

I could do a brute force check

[brittle wadi]

I'm asking you about a bag of zeroes and ones

When will I know that there's no zeroes in the bag?

[brave aspen]

when everything's out

[pale swallow]

That's what it takes to find an item in a list in the worst case scenario.

[brittle wadi]

yes exactly

[brave aspen]

so, brute force it is

[brittle wadi]

what part of your code is looking at everything in the bag?

[brave aspen]

none, since I got return ending the process prematurely

[brittle wadi]

you only need to end the process early if you find a zero

if you go through the whole process without finding a zero, then you can return False

there's no "brute force" about this as there's only a single list and single iteration

[brave aspen]

give me some time to change my code

mylist = [1, 1, 0, 0, 0, 0, 0, 0, 0]
    
def myfunction(mylist):
    for val in mylist:
        if val == 0:
            return True
        else:
            return False
                
print(myfunction(mylist))

is that it?

[brittle wadi]

again, you should not be returning both options within the loop

you can only safely return False after you've looked at every single number in the list

what part of your code is after checking each number?

[brave aspen]

wdym after checking each number?

oh nvm

I gotta check every item, is that what you mean?

[brittle wadi]

that's already what your for loop is doing

do you understand what a for loop does?

[brave aspen]

yeah,

[brittle wadi]

so, if your for loop finishes without returning True, that means there were no zeroes found

if there was a zero, the loop would stop early due to the return

[brave aspen]

in my case, it check the maximum amount of times, as long as the list is going

[brave aspen]

I'm a dumbass

👩‍🦲

[brittle wadi]

These moments never go away 🙂

[light stratus]

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