Question

I have pseudo-code like this:

if( b < a)
   return (1,0)+foo(a-b,b)

I want to write it in python. But can python add tuples? What is the best way to code something like that?

Answer 1

Do you want to do element-wise addition, or to append the tuples? By default python does

(1,2)+(3,4) = (1,2,3,4)

You could define your own as:

def myadd(x,y):
     z = []
     for i in range(len(x)):
         z.append(x[i]+y[i])
     return tuple(z)

Also, as @delnan’s comment makes it clear, this is better written as

def myadd(xs,ys):
     return tuple(x + y for x, y in izip(xs, ys))

or even more functionally:

myadd = lambda xs,ys: tuple(x + y for x, y in izip(xs, ys))

Then do

if( b < a) return myadd((1,0),foo(a-b,b))