[PATCH] Re: samba-tool fsmo transfer - uncaught exception

[Rowland penny]

On 27/05/2019 09:27, Alexander Bokovoy wrote:
> On ma, 27 touko 2019, Rowland penny via samba-technical wrote:
>> On 27/05/2019 02:28, Douglas Bagnall wrote:
>>> On 26/05/19 11:22 PM, Rowland penny wrote:
>>>
>>>> How do you test for something that works on some computers, but not on
>>>> others ?
>>> With Gitlab CI.
>>>
>>>> Which is correct, it working, or it not working ?
>>> Well, when I go
>>>
>>> PYTHONPATH=bin/python python3 -c 'import samba; samba.drs_utils.drsException'
>>>
>>> I get "module 'samba' has no attribute 'drs_utils'".
>>>
>>> Maybe Python 2 was different.
>>>
>>>> If you have a problem with the test, take it up with Andrew, I initially
>>>> created the script following his advice, he later 'improved' it, obviously
>>>> not enough ;-)
>>> Yes. It only tests 'samba-tool fsmo show', not 'seize' and 'transfer'.
>> That is what Andrew wanted at the time, feel free to extend the test.
>>>> Anyway, NACK to your patch, but only because you haven't remove the
>>>> 'import samba' line.
>>> OK, though I don't it would work with the line removed.
>>> For example, it would break
>>>
>>>           forest_dn = samba.dn_from_dns_name(samdb.forest_dns_name())
>>>
>>> and it *might* break other things too because, as discussed, Python
>>> imports can be a bit weird with unexpected side-effects.
>>>
>>> cheers,
>>> Douglas
>> So how do you propose to test for this ? When having just 'import samba'
>> fails for 'samba.drs_utils' but works for 'samba.dn_from_dns_name' ? To me,
>> this looks like a bug in python.
> https://docs.python.org/3/reference/import.html is the canonical
> documentation on how module import works. When you do 'import samba',
> you are importing samba/__init__.py implicitly. That file defines what
> is in the 'samba' namespace as imported. It has no references to
> 'drs_utils' so the only ways to get 'samba.drs_utils' is to do 'from
> samba import drs_utils' or 'import samba.drs_utils' explicitly -- in the
> former case we'll get drs_utils directly, in the latter --
> samba.drs_utils.
>
Thank you very much for explaining that Alexander, much clearer now.

It still doesn't explain why it seemed to work with python2, but I will 
put this down to one of the reasons that python3 was written ;-)

In which case, I remove my 'NACK' and change it to RB+

Rowland