Function that separates a list in two other ones

Function that separates a list in two other ones - Printable Version

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Function that separates a list in two other ones - eevvyy - Dec-07-2017

Hi,

I have an assignment in which I have to write a function that takes a list, separates it in two other lists and return them into a tuple. One list has to consist of 80% of the original one, and the other 20%. My function should be able to take a list of any length, not just one that can be divided by 10, and separate in a similar ratio. So far, my code looks like this:

def sections(liste):
    test = []
    for i in range(int((len(liste) / 100) * 80) , len(liste)): 
        test.append(liste[i])
    train = [x for x in liste if x not in test]
    
    return train, test

Which for this list:

sections([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

Returns this, which is okay:

Output:
([1, 2, 3, 4, 5, 6, 7, 8], [9, 10])

But for this list:

sections([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12])

Returns this:

Output:
([1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12])

But I want this result:

Output:
([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], [11, 12])

I don't really know what to add to my code to make it work like it should, maybe an if statement regarding the length of the list?

Thanks!

RE: Function that separates a list in two other ones - Larz60+ - Dec-07-2017

80% of 12 is 9.6, therefore ([1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12]) is correct

RE: Function that separates a list in two other ones - buran - Dec-07-2017

(Dec-07-2017, 02:16 AM)Larz60+ Wrote: 80% of 12 is 9.6, therefore ([1, 2, 3, 4, 5, 6, 7, 8, 9], [10, 11, 12]) is correct

well, under all math rules 9.6 would round to 10 and i guess that is why OP expects list with len 10 :-)

I also guess OP is using pythin2 thus / is actually floor division.

RE: Function that separates a list in two other ones - Larz60+ - Dec-07-2017

then shouldn't rounding do the trick?

RE: Function that separates a list in two other ones - eevvyy - Dec-07-2017

Thanks! I used round() instead of int() and it worked. I must have been too tired to even think about it :P