GBQ: Updated Documentation, and added method to generic.py

[jacobschaer]

Added some documentation for GBQ module

[jreback]

i led u astray

move to_gbq to core/frame.py (from core/generic.py)
as you only allow data frames (no series or panels)

[jorisvandenbossche]

Should this be something else?

[jreback]

@jacobschaer

actually....instead of moving to core/frame.py, why don't you just check that the obj.ndim==2 and otherwise raise NotImlementedError, that way you can easily support a series at some point in the future if you want, and you get a nice error message (and not AttributeError)

[jtratner]

Not sure if that's the best choice. If we did choose to support it later,
introspection on the object in this version would suggest that this exists
and is supported.

[jreback]

@jacobschaer reverting back......so move to_gbq from core/generic.py to core/frame.py...makes the most sense (we have this with to_stata/to_csv/to_sql as they don't make sense generally for non-frames).

[jreback]

@jacobschaer can you fixup?

[jacobschaer]

@jreback - Sorry about the delay. Docs should be fixed up, and the to_gbq method is in core/frame.py.

[jorisvandenbossche]

When rebasing, you will have to add .. currentmodule:: pandas after this line, because now most functions in api.rst are documented from top-level pandas (#5208).

[jreback]

just a small change; pls squash and i'll merge this

[jacobschaer]

@jreback - Fixed and squashed.

@jorisvandenbossche - Not entirely sure what needed to be done, but I think I did what you asked.

[jorisvandenbossche]

@jacobschaer Indeed, you did what I meant!