Code review comment for lp:~therp-nl/banking-addons/6.0interactive-support_v5_migration

Seems fine to me, well done for the neatness and clarity.

About the iteration on dict:
97 + for table in column_spec.keys():

We should avoid to use dict.keys() because it will build a copy of the list of keys before the iteration, while dict.iterkeys() will never build it.

You can even write
  for table in column_spec:
which is a shorthand for column_spec.iterkeys()

Anyway, here there is only a few keys so it won't really change.

It can be merged.