Question

Right now my function is not recoginizing my numbers in the list coeff as numbers. I am trying to pair up items from the two list and then sort them into a different list based on the value of mul. But everything is going into the negative list. How to i make sure it is considering mul as a number going into each if statement.

def balance_equation(species,coeff):
  data=zip(coeff,species)
  positive=[]
  negative=[]
  for (mul,el) in data:
    if mul<0:
        negative.append((el,mul))
    if mul>0:
        positive.append((el,mul))

Edit;
I ment to originally include this
balance_equation([‘H2O’,’A2′],[‘6′,’-4′])

Answer 1

Your problem is that in the way you call it (balance_equation(['H2O','A2'],['6','-4'])), mul is a string rather than an int ('6' or '-4' rather than 6 or -4). Change your if statement to:

if int(mul)<0:
    negative.append((el,mul))
if int(mul)>0:
    positive.append((el,mul))

This converts mul to an integer before comparing it to 0.