I am trying to subclass pandas' `Timedelta` so when it gets summed by a integer/float, we consider it as a `Timedelta` with seconds.

I tried the following:

```
class Timedelta(pd.Timedelta):
    def __add__(self, other):
        print("OVERRIDEN ADD")
        try:
            print("SUPER ADD")
            return super().__add__(other)
        except:
            print("NEW ADD")
            return super().__add__(Timedelta(str(other)+"s"))

```

But for some reason I can't get it to go to the `"NEW ADD"` implementation:

```
>>> a = Timedelta2('10s')
>>> a+1
OVERRIDEN ADD
Traceback (most recent call last):
  File "C:\Python36\lib\site-packages\IPython\core\interactiveshell.py", line 2910, in run_code
SUPER ADD
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-51-98b939904c8e>", line 1, in <module>
    a+1
TypeError: unsupported operand type(s) for +: 'Timedelta2' and 'int'

```

I was expecting this `TypeError` exception to be caught, but for some reason it isn't, so I would like to ask for some help to figure out what could be happening here.

Thanks!