Python - Negative value with field Calculator

[Pierre-LucBoivin]

Hi,

I'm trying to subtract two integer columns and put the result into a text field. I got good result with positive valuesâ??â??, but I have a problem with negative valuesâ??â??.

[ATTACH=CONFIG]16352[/ATTACH]

Variation column is the result I get with this formula :

def Resultat(x,y):
 diff =  x-y
 return '%d:%02d' % divmod(diff, 60)

Variation = Resultat( !ScePUPbr! , !SitPUPbr!)

Testvari column is the result if I reverse the values â??â??xy

Testvari2 column is the result I should get

Thanks you for help

Pierre-Luc

[Pierre-LucBoivin]

Well still doesn't work ! I'm gonna populate my field testvari2 with an selection and concatenation of the column Variation and testVari !!!

For sure, this is not an optimal solution but it'll work.

!Variation![0:1] + !testvari!

Thanks for your help

[ChristopherThompson]

I guess I am not understanding the value you are trying to obtain - subtracting a smaller number from a larger number will always return a positive value, and it stands to reason that nearly any action taken using that value will also return another positive value. Absolute value doesn't work because by definition absolute value returns a positive value, it doesn't simply reverse the sign.   Now, if the minus sign is simply symbolic of the the difference between the two numbers, then thats somewhat different though misleading.  What was the expression you put into the field calculator to obtain the negative value?  If you're set on getting a negative value there then this will do it i think:

'-%d:%02d' % divmod(4, 60)

[Pierre-LucBoivin]

I absolutely need the negative value because i'm calculating difference between 2 streets network for Emergency travel time. So I need to know the variation(negative or positive) between the different network.

[Pierre-LucBoivin · Accepted solution]

Here the final solution !

def Resultat(x,y):
 diff =  x-y
 if diff < 0:
  sign = '-'
 else:
  sign = ''
 return sign+'%d:%02d' % divmod(abs(diff), 60)

Thanks everyone for your help