I'm assembling code to create pvlib.io.

What functionality is desired? Specifically, from which formats do we want to read, and to which formats do we want to write?

I'm going to focus first on reading a few data formats. I plan to incorporate the current pvlib.tmy which reads tmy2 and tmy3 files, returning a tuple (data, metadata) where data is a pandas DataFrame and metadata is a dict. Any comments on this design? Personally I like it.

I have code to read surfrad files so I'll include that.