diff options
Diffstat (limited to 'doc/release/1.11.0-notes.rst')
| -rw-r--r-- | doc/release/1.11.0-notes.rst | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/doc/release/1.11.0-notes.rst b/doc/release/1.11.0-notes.rst index 0305688d8..770938b60 100644 --- a/doc/release/1.11.0-notes.rst +++ b/doc/release/1.11.0-notes.rst @@ -7,6 +7,8 @@ This release supports Python 2.6 - 2.7 and 3.2 - 3.5. Highlights ========== +* The datetime64 type is now timezone naive. See "datetime64 changes" below + for more details. Build System Changes ==================== @@ -31,6 +33,41 @@ Future Changes Compatibility notes =================== +datetime64 changes +~~~~~~~~~~~~~~~~~~ + +In prior versions of NumPy the experimental datetime64 type always stored +times in UTC. By default, creating a datetime64 object from a string or +printing it would convert from or to local time:: + + # old behavior + >>>> np.datetime64('2000-01-01T00:00:00') + numpy.datetime64('2000-01-01T00:00:00-0800') # note the timezone offset -08:00 + +A concensus of datetime64 users agreed that this behavior is undesirable +and at odds with how datetime64 is usually used (e.g., by pandas_). For +most use cases, a timezone naive datetime type is preferred, similar to the +``datetime.datetime`` type in the Python standard library. Accordingly, +datetime64 no longer assumes that input is in local time, nor does it print +local times:: + + >>>> np.datetime64('2000-01-01T00:00:00') + numpy.datetime64('2000-01-01T00:00:00') + +For backwards compatibility, datetime64 still parses timezone offsets, which +it handles by converting to UTC. However, the resulting datetime is timezone +naive:: + + >>> np.datetime64('2000-01-01T00:00:00-08') + DeprecationWarning: parsing timezone aware datetimes is deprecated; this will raise an error in the future + numpy.datetime64('2000-01-01T08:00:00') + +As a corollary to this change, we no longer prohibit casting between datetimes +with date units and datetimes with timeunits. With timezone naive datetimes, +the rule for casting from dates to times is no longer ambiguous. + +pandas_: http://pandas.pydata.org + DeprecationWarning to error ~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -163,6 +200,10 @@ extended to ``@``, ``numpy.dot``, ``numpy.inner``, and ``numpy.matmul``. **Note:** Requires the transposed and non-transposed matrices to share data. +*np.testing.assert_warns* can now be used as a context manager +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +This matches the behavior of ``assert_raises``. + Changes ======= Pyrex support was removed from ``numpy.distutils``. The method |