doc/source/whatsnew/v0.15.1.rst
.. _whatsnew_0151:
{{ header }}
This is a minor bug-fix release from 0.15.0 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.
Enhancements <whatsnew_0151.enhancements>API Changes <whatsnew_0151.api>Bug Fixes <whatsnew_0151.bug_fixes>.. _whatsnew_0151.api:
API changes
- ``s.dt.hour`` and other ``.dt`` accessors will now return ``np.nan`` for missing values (rather than previously -1), (:issue:`8689`)
.. ipython:: python
s = pd.Series(pd.date_range("20130101", periods=5, freq="D"))
s.iloc[2] = np.nan
s
previous behavior:
.. code-block:: ipython
In [6]: s.dt.hour
Out[6]:
0 0
1 0
2 -1
3 0
4 0
dtype: int64
current behavior:
.. ipython:: python
s.dt.hour
- ``groupby`` with ``as_index=False`` will not add erroneous extra columns to
result (:issue:`8582`):
.. ipython:: python
np.random.seed(2718281)
df = pd.DataFrame(np.random.randint(0, 100, (10, 2)), columns=["jim", "joe"])
df.head()
ts = pd.Series(5 * np.random.randint(0, 3, 10))
previous behavior:
.. code-block:: ipython
In [4]: df.groupby(ts, as_index=False).max()
Out[4]:
NaN jim joe
0 0 72 83
1 5 77 84
2 10 96 65
current behavior:
.. code-block:: ipython
In [4]: df.groupby(ts, as_index=False).max()
Out[4]:
jim joe
0 72 83
1 77 84
2 96 65
- ``groupby`` will not erroneously exclude columns if the column name conflicts
with the grouper name (:issue:`8112`):
.. ipython:: python
df = pd.DataFrame({"jim": range(5), "joe": range(5, 10)})
df
gr = df.groupby(df["jim"] < 2)
previous behavior (excludes 1st column from output):
.. code-block:: ipython
In [4]: gr.apply("sum")
Out[4]:
joe
jim
False 24
True 11
current behavior:
.. ipython:: python
gr.apply("sum")
- Support for slicing with monotonic decreasing indexes, even if ``start`` or ``stop`` is
not found in the index (:issue:`7860`):
.. ipython:: python
s = pd.Series(["a", "b", "c", "d"], [4, 3, 2, 1])
s
previous behavior:
.. code-block:: ipython
In [8]: s.loc[3.5:1.5]
KeyError: 3.5
current behavior:
.. ipython:: python
s.loc[3.5:1.5]
- ``io.data.Options`` has been fixed for a change in the format of the Yahoo Options page (:issue:`8612`), (:issue:`8741`)
.. note::
As a result of a change in Yahoo's option page layout, when an expiry date is given,
``Options`` methods now return data for a single expiry date. Previously, methods returned all
data for the selected month.
The ``month`` and ``year`` parameters have been undeprecated and can be used to get all
options data for a given month.
If an expiry date that is not valid is given, data for the next expiry after the given
date is returned.
Option data frames are now saved on the instance as ``callsYYMMDD`` or ``putsYYMMDD``. Previously
they were saved as ``callsMMYY`` and ``putsMMYY``. The next expiry is saved as ``calls`` and ``puts``.
New features:
- The expiry parameter can now be a single date or a list-like object containing dates.
- A new property ``expiry_dates`` was added, which returns all available expiry dates.
Current behavior:
.. code-block:: ipython
In [17]: from pandas.io.data import Options
In [18]: aapl = Options('aapl', 'yahoo')
In [19]: aapl.get_call_data().iloc[0:5, 0:1]
Out[19]:
Last
Strike Expiry Type Symbol
80 2014-11-14 call AAPL141114C00080000 29.05
84 2014-11-14 call AAPL141114C00084000 24.80
85 2014-11-14 call AAPL141114C00085000 24.05
86 2014-11-14 call AAPL141114C00086000 22.76
87 2014-11-14 call AAPL141114C00087000 21.74
In [20]: aapl.expiry_dates
Out[20]:
[datetime.date(2014, 11, 14),
datetime.date(2014, 11, 22),
datetime.date(2014, 11, 28),
datetime.date(2014, 12, 5),
datetime.date(2014, 12, 12),
datetime.date(2014, 12, 20),
datetime.date(2015, 1, 17),
datetime.date(2015, 2, 20),
datetime.date(2015, 4, 17),
datetime.date(2015, 7, 17),
datetime.date(2016, 1, 15),
datetime.date(2017, 1, 20)]
In [21]: aapl.get_near_stock_price(expiry=aapl.expiry_dates[0:3]).iloc[0:5, 0:1]
Out[21]:
Last
Strike Expiry Type Symbol
109 2014-11-22 call AAPL141122C00109000 1.48
2014-11-28 call AAPL141128C00109000 1.79
110 2014-11-14 call AAPL141114C00110000 0.55
2014-11-22 call AAPL141122C00110000 1.02
2014-11-28 call AAPL141128C00110000 1.32
.. _whatsnew_0151.datetime64_plotting:
- pandas now also registers the ``datetime64`` dtype in matplotlib's units registry
to plot such values as datetimes. This is activated once pandas is imported. In
previous versions, plotting an array of ``datetime64`` values will have resulted
in plotted integer values. To keep the previous behaviour, you can do
``del matplotlib.units.registry[np.datetime64]`` (:issue:`8614`).
.. _whatsnew_0151.enhancements:
Enhancements
concat permits a wider variety of iterables of pandas objects to be
passed as the first parameter (:issue:8645):
.. ipython:: python
from collections import deque
df1 = pd.DataFrame([1, 2, 3]) df2 = pd.DataFrame([4, 5, 6])
previous behavior:
.. code-block:: ipython
In [7]: pd.concat(deque((df1, df2))) TypeError: first argument must be a list-like of pandas objects, you passed an object of type "deque"
current behavior:
.. ipython:: python
pd.concat(deque((df1, df2)))
Represent MultiIndex labels with a dtype that utilizes memory based on the level size. In prior versions, the memory usage was a constant 8 bytes per element in each level. In addition, in prior versions, the reported memory usage was incorrect as it didn't show the usage for the memory occupied by the underling data array. (:issue:8456)
.. ipython:: python
dfi = pd.DataFrame( 1, index=pd.MultiIndex.from_product([["a"], range(1000)]), columns=["A"] )
previous behavior:
.. code-block:: ipython
In [1]: dfi.memory_usage(index=True) Out[1]: Index 8000 # took about 24008 bytes in < 0.15.1 A 8000 dtype: int64
current behavior:
.. ipython:: python
dfi.memory_usage(index=True)
Added Index properties is_monotonic_increasing and is_monotonic_decreasing (:issue:8680).
Added option to select columns when importing Stata files (:issue:7935)
Qualify memory usage in DataFrame.info() by adding + if it is a lower bound (:issue:8578)
Raise errors in certain aggregation cases where an argument such as numeric_only is not handled (:issue:8592).
Added support for 3-character ISO and non-standard country codes in :func:io.wb.download (:issue:8482)
World Bank data requests now will warn/raise based
on an errors argument, as well as a list of hard-coded country codes and
the World Bank's JSON response. In prior versions, the error messages
didn't look at the World Bank's JSON response. Problem-inducing input were
simply dropped prior to the request. The issue was that many good countries
were cropped in the hard-coded approach. All countries will work now, but
some bad countries will raise exceptions because some edge cases break the
entire response. (:issue:8482)
Added option to Series.str.split() to return a DataFrame rather than a Series (:issue:8428)
Added option to df.info(null_counts=None|True|False) to override the default display options and force showing of the null-counts (:issue:8701)
.. _whatsnew_0151.bug_fixes:
Bug fixes
- Bug in unpickling of a ``CustomBusinessDay`` object (:issue:`8591`)
- Bug in coercing ``Categorical`` to a records array, e.g. ``df.to_records()`` (:issue:`8626`)
- Bug in ``Categorical`` not created properly with ``Series.to_frame()`` (:issue:`8626`)
- Bug in coercing in astype of a ``Categorical`` of a passed ``pd.Categorical`` (this now raises ``TypeError`` correctly), (:issue:`8626`)
- Bug in ``cut``/``qcut`` when using ``Series`` and ``retbins=True`` (:issue:`8589`)
- Bug in writing Categorical columns to an SQL database with ``to_sql`` (:issue:`8624`).
- Bug in comparing ``Categorical`` of datetime raising when being compared to a scalar datetime (:issue:`8687`)
- Bug in selecting from a ``Categorical`` with ``.iloc`` (:issue:`8623`)
- Bug in groupby-transform with a Categorical (:issue:`8623`)
- Bug in duplicated/drop_duplicates with a Categorical (:issue:`8623`)
- Bug in ``Categorical`` reflected comparison operator raising if the first argument was a numpy array scalar (e.g. np.int64) (:issue:`8658`)
- Bug in Panel indexing with a list-like (:issue:`8710`)
- Compat issue is ``DataFrame.dtypes`` when ``options.mode.use_inf_as_null`` is True (:issue:`8722`)
- Bug in ``read_csv``, ``dialect`` parameter would not take a string (:issue:`8703`)
- Bug in slicing a MultiIndex level with an empty-list (:issue:`8737`)
- Bug in numeric index operations of add/sub with Float/Index Index with numpy arrays (:issue:`8608`)
- Bug in setitem with empty indexer and unwanted coercion of dtypes (:issue:`8669`)
- Bug in ix/loc block splitting on setitem (manifests with integer-like dtypes, e.g. datetime64) (:issue:`8607`)
- Bug when doing label based indexing with integers not found in the index for
non-unique but monotonic indexes (:issue:`8680`).
- Bug when indexing a Float64Index with ``np.nan`` on numpy 1.7 (:issue:`8980`).
- Fix ``shape`` attribute for ``MultiIndex`` (:issue:`8609`)
- Bug in ``GroupBy`` where a name conflict between the grouper and columns
would break ``groupby`` operations (:issue:`7115`, :issue:`8112`)
- Fixed a bug where plotting a column ``y`` and specifying a label would mutate the index name of the original DataFrame (:issue:`8494`)
- Fix regression in plotting of a DatetimeIndex directly with matplotlib (:issue:`8614`).
- Bug in ``date_range`` where partially-specified dates would incorporate current date (:issue:`6961`)
- Bug in Setting by indexer to a scalar value with a mixed-dtype ``Panel4d`` was failing (:issue:`8702`)
- Bug where ``DataReader``'s would fail if one of the symbols passed was invalid. Now returns data for valid symbols and np.nan for invalid (:issue:`8494`)
- Bug in ``get_quote_yahoo`` that wouldn't allow non-float return values (:issue:`5229`).
.. _whatsnew_0.15.1.contributors:
Contributors
.. contributors:: v0.15.0..v0.15.1