ValueError: setting an array element with a sequence.
This works fine:

```
In [24]: np.asarray(np.array([np.asarray([10, 20])]), np.float32)

Out[24]:
array([[ 10.,  20.]], dtype=float32)
```

but this does not work:

```
In [25]: np.asarray(pd.Series([np.asarray([10, 20])]), np.float32)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-25-afb8b06bdf8c> in <module>()
----> 1 np.asarray(pd.Series([np.asarray([10, 20])]), np.float32)

/usr/local/lib/python2.7/dist-packages/numpy/core/numeric.pyc in asarray(a, dtype, order)
    460 
    461     """
--> 462     return array(a, dtype, copy=False, order=order)
    463 
    464 def asanyarray(a, dtype=None, order=None):

ValueError: setting an array element with a sequence.
```
