# I want product of the outgoing vertices as product of variables but it gives nonint type erros [closed]

nonint error types:

```
dia = DiGraph({'x0':{'x1':(1, -1),'y1':(1, -1),'x2':(1, -1)},'y2':{'x0':(1, -1),'x1':(1, -1)}})
diaout = dia.neighbors_out('x0');diaout
prod(p for p in diaout)
TypeError: can't multiply sequence by non-int of type 'str'\n"}︡{"done":true}︡
```

Hi Biswajit! (If you are the one I remember from IMSc.) What is your actual goal here? I think the problem is you are trying to multiply a bunch of strings together - that is what

`diaout`

will give you - so you would have to make them mathematical variables or something first. What would multiplying strings even mean?You can do

`' * '.join(diaout)`

to get a string representing the product. Is that what you want?I see now that this has been answered in sage-combinat-devel: https://groups.google.com/d/msg/sage-...