get positive number from a list if there's the same number but negative

get positive number from a list if there's the same number but negative - Printable Version

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get positive number from a list if there's the same number but negative - haye - Nov-07-2017

list_one = [-8, 8, 144, 17]

def test(lis):
    return min(lis, key=abs)

print test(list_one)

Output:
-8

i want to print the closest number to 0 from a list,
in this case, -8 and 8 are the two closest number to 0, but i get the first number of the list(-8), and i would like that if there is two numbers which are as close each other to 0 (so like in this case, -8 and 8) I'd like to get the positive number ( so 8 )
how could i do that , thanks

well, resolved doing this,

list_one = [-8, 8, 144, 17]
 
def test(lis):
    m = min(lis, key=abs)
    if m < 0:
        if m and m*-1 in lis:
            return m*-1
        else:
            return m
    else:
        return m

print test(list_one)

new output :

Output:
8

was there a simpler way ?

RE: get positive number from a list if there's the same number but negative - DeaD_EyE - Nov-07-2017

Yes

list_one = [-8, 8, 144, 17]
min(filter(lambda x: x >= 0, list_one))

RE: get positive number from a list if there's the same number but negative - haye - Nov-07-2017

i will look at it , thanks

RE: get positive number from a list if there's the same number but negative - heiner55 - Nov-07-2017

With the list = [-8, 144, 17]
I get -8 with first programm
and 17 with second program.

RE: get positive number from a list if there's the same number but negative - haye - Nov-07-2017

hi heiner, this is weird, it's not the case for me,
with first program, i get -8
with second program, -8 too

RE: get positive number from a list if there's the same number but negative - heiner55 - Nov-07-2017

Take my list = [-8, 144, 17], not the original one.

RE: get positive number from a list if there's the same number but negative - haye - Nov-07-2017

this is what i did :

list_one = [-8, 144, 17]
 
def test(lis):
    return min(lis, key=abs)
 
print test(list_one)

Output:
-8

----

list_one = [-8, 8, 144, 17]
  
def test(lis):
    m = min(lis, key=abs)
    if m < 0:
        if m and m*-1 in lis:
            return m*-1
        else:
            return m
    else:
        return m
 
print test(list_one)

Output:
-8

RE: get positive number from a list if there's the same number but negative - heiner55 - Nov-07-2017

Sorry, with second program, I meant this:

list_one = [-8, 144, 17]
print(min(filter(lambda x: x >= 0, list_one)))

RE: get positive number from a list if there's the same number but negative - haye - Nov-07-2017

oh yes, you're right, it seems to work only for positives numbers, i finally used this way:

list_one = [-8, 8, 144, 17]
def test(lis):
    m = min(lis, key=abs)
    if m and -m in lis:
        return abs(m)
    else:
        return m

print test(list_one)

Output:
8

and with you're list:

list_one = [-8,  144, 17]
def test(lis):
    m = min(lis, key=abs)
    if m and -m in lis:
        return abs(m)
    else:
        return m

print test(list_one)

Output:
-8

RE: get positive number from a list if there's the same number but negative - heiner55 - Nov-07-2017

Why
if m and -m in lis:
and not only:
if -m in lis:
?

I think "if m" is always true (except 0).
Or did you mean:
if m in list and -m in list: