What does ty(val) mean?

[liagym]

In the following code:

>>> line='yosi, 1, 3.14'
>>> types=[str, int, float]
>>> raw=line.split(',')
>>> raw
['yosi', ' 1', ' 3.14']
>>> fields = [ty(val) for ty,val in zip(types,raw)]
>>> fields
['yosi', 1, 3.14]

What do ty and val refer to?