ESO query functions - order retrieved table columns as in the list passed to the function

[juanmcloaiza]

Version 0.4.12.dev10525

>>> import astroquery as aq
>>> aq.__version__
'0.4.12.dev10525'

Observed behavior:

The columns of the retrieved table are not ordered as in the list provided by the user.

>>> from astroquery.eso import Eso
>>> eso = Eso()
>>> eso.query_main(columns = ['dp_id', 'dec', 'ra' ])[:0]
<Table length=0>
   ra     dec   dp_id
  deg     deg
float64 float64 object
------- ------- ------

Expected behavior:

The columns of the retrieved table are ordered as in the list provided by the user.

>>> from astroquery.eso import Eso
>>> eso = Eso()
>>> eso.query_main(columns = ['dp_id', 'dec', 'ra' ])[:0]
<Table length=0>
dp_id    dec      ra
         deg     deg
object float64 float64
------ ------- -------

How to reproduce:

... see snippets above. This happens for all ESO functions query_*(...).

[bsipocz]

Hmm, I suppose we return the result as it comes back from the server and if there is no server side ordering this is what we get. I don't see this as a bug, but happy to merge a PR if you as ESO maintainer think we should have the expected behaviour from above.