Lad wrote:
> Let's suppose I have
>
> a={'c':1,'d':2}
> b={'c':2}
> but
> a.update(b)
> will make
> {'c': 2, 'd': 2}
>
> and I would need
> {'c': 3, 'd': 2}
>
> (because `c` is 1 in `a` dictionary and `c` is 2 in `b` dictionary, so
> 1+2=3)
>
> How can be done that?
dict([(k, a.get(k, 0) + b.get(k,0)) for k in set(a.keys() + b.keys())])