* I have an index value called `new_c[a]`. `new_c[a] == [1,2,3]`
* I have a list of sets called `check_com_of_three`. Which is `[(4,5,6), (7,8,9)]`.
* I would like to join `set(new_c[a])` with `check_com_of_three`.

(eg. `[(1,2,3),(4,5,6),(7,8,9)]`)

I'm using set to make sure there are no repeating sets in `set(check_com_of_three)`

```
>>>set(new_c[a]) + str(',') + set(check_com_of_three)

```

Output
------

```
Traceback (most recent call last):
  File "<pyshell#34>", line 1, in <module>
    set(new_c[a]) + str(',') + set(check_com_of_three)
TypeError: unsupported operand type(s) for +: 'set' and 'str'

```

Any explanation as to why I'm doing this wrong, and what is the best and easiest method to do this?