-
-
Notifications
You must be signed in to change notification settings - Fork 18.4k
/
Copy pathv0.17.0.txt
136 lines (82 loc) · 4.89 KB
/
v0.17.0.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
.. _whatsnew_0170:
v0.17.0 (July 31, 2015)
-----------------------
This is a major release from 0.16.2 and includes a small number of API changes, several new features,
enhancements, and performance improvements along with a large number of bug fixes. We recommend that all
users upgrade to this version.
.. warning::
pandas >= 0.17.0 will no longer support compatibility with Python version 3.2 (:issue:`9118`)
Highlights include:
- Release the Global Interpreter Lock (GIL) on some cython operations, see :ref:`here <whatsnew_0170.gil>`
Check the :ref:`API Changes <whatsnew_0170.api>` and :ref:`deprecations <whatsnew_0170.deprecations>` before updating.
.. contents:: What's new in v0.17.0
:local:
:backlinks: none
.. _whatsnew_0170.enhancements:
New features
~~~~~~~~~~~~
- SQL io functions now accept a SQLAlchemy connectable. (:issue:`7877`)
.. _whatsnew_0170.enhancements.other:
Other enhancements
^^^^^^^^^^^^^^^^^^
- ``.as_blocks`` will now take a ``copy`` optional argument to return a copy of the data, default is to copy (no change in behavior from prior versions), (:issue:`9607`)
.. _whatsnew_0170.api:
Backwards incompatible API changes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. _whatsnew_0170.api_breaking:
.. _whatsnew_0170.api_breaking.other:
Other API Changes
^^^^^^^^^^^^^^^^^
- Enable writing Excel files in :ref:`memory <_io.excel_writing_buffer>` using StringIO/BytesIO (:issue:`7074`)
- Enable serialization of lists and dicts to strings in ExcelWriter (:issue:`8188`)
- Allow passing `kwargs` to the interpolation methods (:issue:`10378`).
.. _whatsnew_0170.deprecations:
Deprecations
^^^^^^^^^^^^
.. _whatsnew_0170.prior_deprecations:
Removal of prior version deprecations/changes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. _dask: https://dask.readthedocs.org/en/latest/
.. _whatsnew_0170.gil:
Releasing the GIL
~~~~~~~~~~~~~~~~~
We are releasing the global-interpreter-lock (GIL) on some cython operations.
This will allow other threads to run simultaneously during computation, potentially allowing performance improvements
from multi-threading. Notably ``groupby`` and some indexing operations are a benefit from this. (:issue:`8882`)
For example the groupby expression in the following code will have the GIL released during the factorization step, e.g. ``df.groupby('key')``
as well as the ``.sum()`` operation.
.. code-block:: python
N = 1e6
df = DataFrame({'key' : np.random.randint(0,ngroups,size=N),
'data' : np.random.randn(N) })
df.groupby('key')['data'].sum()
Releasing of the GIL could benefit an application that uses threads for user interactions (e.g. ``QT``), or performaning multi-threaded computations. A nice example of a library that can handle these types of computation-in-parallel is the dask_ library.
.. _whatsnew_0170.performance:
Performance Improvements
~~~~~~~~~~~~~~~~~~~~~~~~
- Added vbench benchmarks for alternative ExcelWriter engines and reading Excel files (:issue:`7171`)
- 4x improvement in ``timedelta`` string parsing (:issue:`6755`, :issue:`10426`)
- 8x improvement in ``timedelta64`` and ``datetime64`` ops (:issue:`6755`)
- Significantly improved performance of indexing ``MultiIndex`` with slicers (:issue:`10287`)
- Improved performance of ``Series.isin`` for datetimelike/integer Series (:issue:`10287`)
.. _whatsnew_0170.bug_fixes:
Bug Fixes
~~~~~~~~~
- Bug in ``DataFrame.apply`` when function returns categorical series. (:issue:`9573`)
- Bug in ``Index.drop_duplicates`` dropping name(s) (:issue:`10115`)
- Bug in ``pd.Series`` when setting a value on an empty ``Series`` whose index has a frequency. (:issue:`10193`)
- Bug in ``DataFrame.plot`` raises ``ValueError`` when color name is specified by multiple characters (:issue:`10387`)
- Bug in ``DataFrame.reset_index`` when index contains `NaT`. (:issue:`10388`)
- Bug in ``ExcelReader`` when worksheet is empty (:issue:`6403`)
- Bug in ``Table.select_column`` where name is not preserved (:issue:`10392`)
- Bug in ``offsets.generate_range`` where ``start`` and ``end`` have finer precision than ``offset`` (:issue:`9907`)
- Bug in ``DataFrame.interpolate`` with ``axis=1`` and ``inplace=True`` (:issue:`10395`)
- Bug in ``io.sql.get_schema`` when specifying multiple columns as primary
key (:issue:`10385`).
- Bug in ``test_categorical`` on big-endian builds (:issue:`10425`)
- Bug in ``Series.map`` using categorical ``Series`` raises ``AttributeError`` (:issue:`10324`)
- Bug in ``MultiIndex.get_level_values`` including ``Categorical`` raises ``AttributeError`` (:issue:`10460`)
- Bug that caused segfault when resampling an empty Series (:issue:`10228`)
- Bug in ``DatetimeIndex`` and ``PeriodIndex.value_counts`` resets name from its result, but retains in result's ``Index``. (:issue:`10150`)
- Bug in `pandas.concat` with ``axis=0`` when column is of dtype ``category`` (:issue:`10177`)
- Bug in ``read_msgpack`` where input type is not always checked (:issue:`10369`)