Re: hstore_plpython regression test does not work on Python 3

22.05.2015, 09:44, Christian Ullrich kirjoitti:
> * Peter Eisentraut wrote:
>> On 5/16/15 12:06 PM, Tom Lane wrote:
>>> As exhibited for instance here:
>>>
>>> http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=spoonbill&dt=2015-05-16%2011%3A00%3A07
>>>
>>>
>>> I've been able to replicate this on a Fedora 21 box: works fine with
>>> Python 2, fails with Python 3. Seems like we still have an issue
>>> with reliance on a system-provided sort method.
>>
>> Pushed a fix, tested with 2.3 .. 3.4.
>
> There is still a sorting problem (of sorts). jaguarundi [1] keeps
> failing intermittently like this:
>
> *** 47,53 ****
> return len(val)
> $$;
> SELECT test1arr(array['aa=>bb, cc=>NULL'::hstore, 'dd=>ee']);
> ! INFO: [{'aa': 'bb', 'cc': None}, {'dd': 'ee'}]
> CONTEXT: PL/Python function "test1arr"
> test1arr
> ----------
> --- 47,53 ----
> return len(val)
> $$;
> SELECT test1arr(array['aa=>bb, cc=>NULL'::hstore, 'dd=>ee']);
> ! INFO: [{'cc': None, 'aa': 'bb'}, {'dd': 'ee'}]
> CONTEXT: PL/Python function "test1arr"
> test1arr
> ----------
>
> I cannot find any other animal that does the same, but I doubt it's due
> to CCA this time.
>
> Should dict tests perhaps output sorted(thedict.items()) instead?
> Testing dict formatting could be done with single-item dicts.
>
> [1] http://pgbuildfarm.org/cgi-bin/show_history.pl?nm=jaguarundi&br=HEAD

Looks like that animal uses Python 3.4. Python 3.3 and newer versions
default to using a random seed for hashing objects into dicts which
makes the order of dict elements random; see
https://docs.python.org/3/using/cmdline.html#cmdoption-R

The test case could be changed to use sorted(dict.items()) always, but
there are multiple places where it would need to be applied. Setting
the PYTHONHASHSEED environment variable to a stable value would probably
be easier.

/ Oskari