I have an rdd which I create from an input like the following:

```
0 1
0 2
1 2
1 3

```

I do a groupBy like the following:

```
rdd2 = rdd1.groupBy(lambda x: x[0])

```

Now rdd2 would be something like:

```
[(0,[1,2]),(1,[2,3])]

```

MY questions is, how can I get the size of that list associated with each element?

Thanks