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#135 ✓resolved
Psycopg website

Incorrect psycopg2.tz.FixedOffsetTimezone after pickling datetimes with different timezones

Reported by Psycopg website | 2012-10-21 18:44:58 UTC

Submitted by: Robert Saint

>>> before_pickling = []
>>> cur.execute("SET TIME ZONE 'Europe/Rome';")  # UTC + 1 hour
>>> cur.execute("SELECT '2010-01-01 10:30:45'::timestamptz;")
>>> before_pickling.append(cur.fetchone()[0])
>>> cur.execute("SET TIME ZONE 'Europe/Moscow';")  # UTC + 3 hour
>>> cur.execute("SELECT '2010-01-01 10:30:45'::timestamptz;")
>>> before_pickling.append(cur.fetchone()[0])
>>> print before_pickling
[datetime.datetime(2010, 1, 1, 10, 30, 45, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=60, name=None)), 
    datetime.datetime(2010, 1, 1, 10, 30, 45, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=180, name=None))]
>>> after_pickling = pickle.loads(pickle.dumps(before_pickling))
>>> print before_pickling == after_pickling
False
>>> print after_pickling
[datetime.datetime(2010, 1, 1, 10, 30, 45, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=180, name=None)), 
    datetime.datetime(2010, 1, 1, 10, 30, 45, tzinfo=psycopg2.tz.FixedOffsetTimezone(offset=180, name=None))]

Comments and changes to this ticket

  • Daniele Varrazzo

    Daniele Varrazzo 2012-10-21 19:38:09 UTC

    • State changed from “new” to “open”
    • Tag cleared.

    What the... Confirmed.

  • Daniele Varrazzo

    Daniele Varrazzo 2012-10-21 19:46:04 UTC

    Minimal test:

    In [1]: import psycopg2.tz

In [2]: import pickle

In [3]: pickle.loads(pickle.dumps([psycopg2.tz.FixedOffsetTimezone(offset=60), 
    psycopg2.tz.FixedOffsetTimezone(offset=180)]))
Out[3]: 
[psycopg2.tz.FixedOffsetTimezone(offset=180, name=None),
 psycopg2.tz.FixedOffsetTimezone(offset=180, name=None)]
  • Daniele Varrazzo

    Daniele Varrazzo 2012-10-21 21:06:39 UTC

    • State changed from “open” to “resolved”

    Fixed in my devel and 2.4 maint branch

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Psycopg is the most used PostgreSQL adapter for the Python programming language. At the core it fully implements the Python DB API 2.0 specifications. Several extensions allow access to many of the features offered by PostgreSQL.

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