fix conflict

asv_bench/benchmarks/series_methods.py

@@ -124,6 +124,25 @@ def time_dropna(self, dtype):
         self.s.dropna()
 
 
+class SearchSorted(object):
+
+    goal_time = 0.2
+    params = ['int8', 'int16', 'int32', 'int64',
+              'uint8', 'uint16', 'uint32', 'uint64',
+              'float16', 'float32', 'float64',
+              'str']
+    param_names = ['dtype']
+
+    def setup(self, dtype):
+        N = 10**5
+        data = np.array([1] * N + [2] * N + [3] * N).astype(dtype)
+        self.s = Series(data)
+
+    def time_searchsorted(self, dtype):
+        key = '2' if dtype == 'str' else 2
+        self.s.searchsorted(key)
+
+
 class Map(object):
 
     params = ['dict', 'Series']

doc/source/user_guide/timeseries.rst

@@ -633,6 +633,16 @@ We are stopping on the included end-point as it is part of the index:
    dft2 = dft2.swaplevel(0, 1).sort_index()
    dft2.loc[idx[:, '2013-01-05'], :]
 
+.. versionadded:: 0.25.0
+
+Slicing with string indexing also honors UTC offset.
+
+.. ipython:: python
+
+    df = pd.DataFrame([0], index=pd.DatetimeIndex(['2019-01-01'], tz='US/Pacific'))
+    df
+    df['2019-01-01 12:00:00+04:00':'2019-01-01 13:00:00+04:00']
+
 .. _timeseries.slice_vs_exact_match:
 
 Slice vs. Exact Match

doc/source/whatsnew/v0.24.2.rst

@@ -96,7 +96,7 @@ Bug Fixes
 **Other**
 
 - Bug in :meth:`Series.is_unique` where single occurrences of ``NaN`` were not considered unique (:issue:`25180`)
--
+- Bug in :func:`merge` when merging an empty ``DataFrame`` with an ``Int64`` column or a non-empty ``DataFrame`` with an ``Int64`` column that is all ``NaN`` (:issue:`25183`)
 -
 
 .. _whatsnew_0.242.contributors:

doc/source/whatsnew/v0.25.0.rst

@@ -23,13 +23,46 @@ Other Enhancements
 - :meth:`Timestamp.replace` now supports the ``fold`` argument to disambiguate DST transition times (:issue:`25017`)
 - :meth:`DataFrame.at_time` and :meth:`Series.at_time` now support :meth:`datetime.time` objects with timezones (:issue:`24043`)
 - ``Series.str`` has gained :meth:`Series.str.casefold` method to removes all case distinctions present in a string (:issue:`25405`)
+- :meth:`DataFrame.set_index` now works for instances of ``abc.Iterator``, provided their output is of the same length as the calling frame (:issue:`22484`, :issue:`24984`)
+- :meth:`DatetimeIndex.union` now supports the ``sort`` argument. The behaviour of the sort parameter matches that of :meth:`Index.union` (:issue:`24994`)
+-
 
 .. _whatsnew_0250.api_breaking:
 
 Backwards incompatible API changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- :meth:`Timestamp.strptime` will now raise a NotImplementedError (:issue:`25016`)
+.. _whatsnew_0250.api_breaking.utc_offset_indexing:
+
+Indexing with date strings with UTC offsets
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Indexing a :class:`DataFrame` or :class:`Series` with a :class:`DatetimeIndex` with a
+date string with a UTC offset would previously ignore the UTC offset. Now, the UTC offset
+is respected in indexing. (:issue:`24076`, :issue:`16785`)
+
+*Previous Behavior*:
+
+.. code-block:: ipython
+
+    In [1]: df = pd.DataFrame([0], index=pd.DatetimeIndex(['2019-01-01'], tz='US/Pacific'))
+
+    In [2]: df
+    Out[2]:
+                               0
+    2019-01-01 00:00:00-08:00  0
+
+    In [3]: df['2019-01-01 00:00:00+04:00':'2019-01-01 01:00:00+04:00']
+    Out[3]:
+                               0
+    2019-01-01 00:00:00-08:00  0
+
+*New Behavior*:
+
+.. ipython:: ipython
+
+    df = pd.DataFrame([0], index=pd.DatetimeIndex(['2019-01-01'], tz='US/Pacific'))
+    df['2019-01-01 12:00:00+04:00':'2019-01-01 13:00:00+04:00']
 
 .. _whatsnew_0250.api.other:
 
@@ -38,7 +71,7 @@ Other API Changes
 
 - :class:`DatetimeTZDtype` will now standardize pytz timezones to a common timezone instance (:issue:`24713`)
 - ``Timestamp`` and ``Timedelta`` scalars now implement the :meth:`to_numpy` method as aliases to :meth:`Timestamp.to_datetime64` and :meth:`Timedelta.to_timedelta64`, respectively. (:issue:`24653`)
--
+- :meth:`Timestamp.strptime` will now rise a ``NotImplementedError`` (:issue:`25016`)
 -
 
 .. _whatsnew_0250.deprecations:
@@ -64,7 +97,8 @@ Performance Improvements
 
 - Significant speedup in `SparseArray` initialization that benefits most operations, fixing performance regression introduced in v0.20.0 (:issue:`24985`)
 - `DataFrame.to_stata()` is now faster when outputting data with any string or non-native endian columns (:issue:`25045`)
--
+- Improved performance of :meth:`Series.searchsorted`. The speedup is especially large when the dtype is
+  int8/int16/int32 and the searched key is within the integer bounds for the dtype (:issue:`22034`)
 
 
 .. _whatsnew_0250.bug_fixes:

pandas/compat/__init__.py

@@ -137,6 +137,7 @@ def lfilter(*args, **kwargs):
     reload = reload
     Hashable = collections.abc.Hashable
     Iterable = collections.abc.Iterable
+    Iterator = collections.abc.Iterator
     Mapping = collections.abc.Mapping
     MutableMapping = collections.abc.MutableMapping
     Sequence = collections.abc.Sequence
@@ -199,6 +200,7 @@ def get_range_parameters(data):
 
     Hashable = collections.Hashable
     Iterable = collections.Iterable
+    Iterator = collections.Iterator
     Mapping = collections.Mapping
     MutableMapping = collections.MutableMapping
     Sequence = collections.Sequence

pandas/core/algorithms.py

@@ -19,7 +19,7 @@
     ensure_float64, ensure_int64, ensure_object, ensure_platform_int,
     ensure_uint64, is_array_like, is_bool_dtype, is_categorical_dtype,
     is_complex_dtype, is_datetime64_any_dtype, is_datetime64tz_dtype,
-    is_datetimelike, is_extension_array_dtype, is_float_dtype,
+    is_datetimelike, is_extension_array_dtype, is_float_dtype, is_integer,
     is_integer_dtype, is_interval_dtype, is_list_like, is_numeric_dtype,
     is_object_dtype, is_period_dtype, is_scalar, is_signed_integer_dtype,
     is_sparse, is_timedelta64_dtype, is_unsigned_integer_dtype,
@@ -1724,6 +1724,89 @@ def func(arr, indexer, out, fill_value=np.nan):
     return out
 
 
+# ------------ #
+# searchsorted #
+# ------------ #
+
+def searchsorted(arr, value, side="left", sorter=None):
+    """
+    Find indices where elements should be inserted to maintain order.
+
+    .. versionadded:: 0.25.0
+
+    Find the indices into a sorted array `arr` (a) such that, if the
+    corresponding elements in `value` were inserted before the indices,
+    the order of `arr` would be preserved.
+
+    Assuming that `arr` is sorted:
+
+    ======  ================================
+    `side`  returned index `i` satisfies
+    ======  ================================
+    left    ``arr[i-1] < value <= self[i]``
+    right   ``arr[i-1] <= value < self[i]``
+    ======  ================================
+
+    Parameters
+    ----------
+    arr: array-like
+        Input array. If `sorter` is None, then it must be sorted in
+        ascending order, otherwise `sorter` must be an array of indices
+        that sort it.
+    value : array_like
+        Values to insert into `arr`.
+    side : {'left', 'right'}, optional
+        If 'left', the index of the first suitable location found is given.
+        If 'right', return the last such index.  If there is no suitable
+        index, return either 0 or N (where N is the length of `self`).
+    sorter : 1-D array_like, optional
+        Optional array of integer indices that sort array a into ascending
+        order. They are typically the result of argsort.
+
+    Returns
+    -------
+    array of ints
+        Array of insertion points with the same shape as `value`.
+
+    See Also
+    --------
+    numpy.searchsorted : Similar method from NumPy.
+    """
+    if sorter is not None:
+        sorter = ensure_platform_int(sorter)
+
+    if isinstance(arr, np.ndarray) and is_integer_dtype(arr) and (
+            is_integer(value) or is_integer_dtype(value)):
+        from .arrays.array_ import array
+        # if `arr` and `value` have different dtypes, `arr` would be
+        # recast by numpy, causing a slow search.
+        # Before searching below, we therefore try to give `value` the
+        # same dtype as `arr`, while guarding against integer overflows.
+        iinfo = np.iinfo(arr.dtype.type)
+        value_arr = np.array([value]) if is_scalar(value) else np.array(value)
+        if (value_arr >= iinfo.min).all() and (value_arr <= iinfo.max).all():
+            # value within bounds, so no overflow, so can convert value dtype
+            # to dtype of arr
+            dtype = arr.dtype
+        else:
+            dtype = value_arr.dtype
+
+        if is_scalar(value):
+            value = dtype.type(value)
+        else:
+            value = array(value, dtype=dtype)
+    elif not (is_object_dtype(arr) or is_numeric_dtype(arr) or
+              is_categorical_dtype(arr)):
+        from pandas.core.series import Series
+        # E.g. if `arr` is an array with dtype='datetime64[ns]'
+        # and `value` is a pd.Timestamp, we may need to convert value
+        value_ser = Series(value)._values
+        value = value_ser[0] if is_scalar(value) else value_ser
+
+    result = arr.searchsorted(value, side=side, sorter=sorter)
+    return result
+
+
 # ---- #
 # diff #
 # ---- #

pandas/core/arrays/base.py

@@ -555,17 +555,17 @@ def searchsorted(self, value, side="left", sorter=None):
         .. versionadded:: 0.24.0
 
         Find the indices into a sorted array `self` (a) such that, if the
-        corresponding elements in `v` were inserted before the indices, the
-        order of `self` would be preserved.
+        corresponding elements in `value` were inserted before the indices,
+        the order of `self` would be preserved.
 
-        Assuming that `a` is sorted:
+        Assuming that `self` is sorted:
 
-        ======  ============================
+        ======  ================================
         `side`  returned index `i` satisfies
-        ======  ============================
-        left    ``self[i-1] < v <= self[i]``
-        right   ``self[i-1] <= v < self[i]``
-        ======  ============================
+        ======  ================================
+        left    ``self[i-1] < value <= self[i]``
+        right   ``self[i-1] <= value < self[i]``
+        ======  ================================
 
         Parameters
         ----------
@@ -581,7 +581,7 @@ def searchsorted(self, value, side="left", sorter=None):
 
         Returns
         -------
-        indices : array of ints
+        array of ints
             Array of insertion points with the same shape as `value`.
 
         See Also

pandas/core/arrays/numpy_.py

@@ -4,6 +4,7 @@
 
 from pandas._libs import lib
 from pandas.compat.numpy import function as nv
+from pandas.util._decorators import Appender
 from pandas.util._validators import validate_fillna_kwargs
 
 from pandas.core.dtypes.dtypes import ExtensionDtype
@@ -12,6 +13,7 @@
 
 from pandas import compat
 from pandas.core import nanops
+from pandas.core.algorithms import searchsorted
 from pandas.core.missing import backfill_1d, pad_1d
 
 from .base import ExtensionArray, ExtensionOpsMixin
@@ -423,6 +425,11 @@ def to_numpy(self, dtype=None, copy=False):
 
         return result
 
+    @Appender(ExtensionArray.searchsorted.__doc__)
+    def searchsorted(self, value, side='left', sorter=None):
+        return searchsorted(self.to_numpy(), value,
+                            side=side, sorter=sorter)
+
     # ------------------------------------------------------------------------
     # Ops
 

pandas/core/base.py

@@ -1522,11 +1522,11 @@ def factorize(self, sort=False, na_sentinel=-1):
         array([3])
         """)
 
-    @Substitution(klass='IndexOpsMixin')
+    @Substitution(klass='Index')
     @Appender(_shared_docs['searchsorted'])
     def searchsorted(self, value, side='left', sorter=None):
-        # needs coercion on the key (DatetimeIndex does already)
-        return self._values.searchsorted(value, side=side, sorter=sorter)
+        return algorithms.searchsorted(self._values, value,
+                                       side=side, sorter=sorter)
 
     def drop_duplicates(self, keep='first', inplace=False):
         inplace = validate_bool_kwarg(inplace, 'inplace')

pandas/core/frame.py

@@ -33,7 +33,7 @@
 
 from pandas import compat
 from pandas.compat import (range, map, zip, lmap, lzip, StringIO, u,
-                           PY36, raise_with_traceback,
+                           PY36, raise_with_traceback, Iterator,
                            string_and_binary_types)
 from pandas.compat.numpy import function as nv
 from pandas.core.dtypes.cast import (
@@ -4025,7 +4025,8 @@ def set_index(self, keys, drop=True, append=False, inplace=False,
             This parameter can be either a single column key, a single array of
             the same length as the calling DataFrame, or a list containing an
             arbitrary combination of column keys and arrays. Here, "array"
-            encompasses :class:`Series`, :class:`Index` and ``np.ndarray``.
+            encompasses :class:`Series`, :class:`Index`, ``np.ndarray``, and
+            instances of :class:`abc.Iterator`.
         drop : bool, default True
             Delete columns to be used as the new index.
         append : bool, default False
@@ -4104,6 +4105,32 @@ def set_index(self, keys, drop=True, append=False, inplace=False,
         if not isinstance(keys, list):
             keys = [keys]
 
+        err_msg = ('The parameter "keys" may be a column key, one-dimensional '
+                   'array, or a list containing only valid column keys and '
+                   'one-dimensional arrays.')
+
+        missing = []
+        for col in keys:
+            if isinstance(col, (ABCIndexClass, ABCSeries, np.ndarray,
+                                list, Iterator)):
+                # arrays are fine as long as they are one-dimensional
+                # iterators get converted to list below
+                if getattr(col, 'ndim', 1) != 1:
+                    raise ValueError(err_msg)
+            else:
+                # everything else gets tried as a key; see GH 24969
+                try:
+                    found = col in self.columns
+                except TypeError:
+                    raise TypeError(err_msg + ' Received column of '
+                                    'type {}'.format(type(col)))
+                else:
+                    if not found:
+                        missing.append(col)
+
+        if missing:
+            raise KeyError('None of {} are in the columns'.format(missing))
+
         if inplace:
             frame = self
         else:
@@ -4132,13 +4159,25 @@ def set_index(self, keys, drop=True, append=False, inplace=False,
             elif isinstance(col, (list, np.ndarray)):
                 arrays.append(col)
                 names.append(None)
+            elif isinstance(col, Iterator):
+                arrays.append(list(col))
+                names.append(None)
             # from here, col can only be a column label
             else:
                 arrays.append(frame[col]._values)
                 names.append(col)
                 if drop:
                     to_remove.append(col)
 
+            if len(arrays[-1]) != len(self):
+                # check newest element against length of calling frame, since
+                # ensure_index_from_sequences would not raise for append=False.
+                raise ValueError('Length mismatch: Expected {len_self} rows, '
+                                 'received array of length {len_col}'.format(
+                                     len_self=len(self),
+                                     len_col=len(arrays[-1])
+                                 ))
+
         index = ensure_index_from_sequences(arrays, names)
 
         if verify_integrity and not index.is_unique: