Add month names

Fix localiztion of months

Add series test and whatsnew notes

Modify test and lint

Add Timestamp rst

Author: mroeschke

Diff for: doc/source/api.rst

@@ -497,6 +497,7 @@ These can be accessed like ``Series.dt.<property>``.
    Series.dt.time
    Series.dt.year
    Series.dt.month
+   Series.dt.month_name
    Series.dt.day
    Series.dt.hour
    Series.dt.minute
@@ -1537,6 +1538,7 @@ Time/Date Components
 
    DatetimeIndex.year
    DatetimeIndex.month
+   DatetimeIndex.month_name
    DatetimeIndex.day
    DatetimeIndex.hour
    DatetimeIndex.minute
@@ -1757,6 +1759,7 @@ Properties
     Timestamp.microsecond
     Timestamp.min
     Timestamp.month
+    Timestamp.month_name
     Timestamp.nanosecond
     Timestamp.quarter
     Timestamp.resolution

Diff for: doc/source/whatsnew/v0.21.1.txt

@@ -22,8 +22,8 @@ Other Enhancements
 ^^^^^^^^^^^^^^^^^^
 
 - :meth:`Timestamp.timestamp` is now available in Python 2.7. (:issue:`17329`)
--
--
+- :attr:`Timestamp.month_name`, :attr:`DatetimeIndex.month_name`, and :attr:`Series.dt.month_name` are now available (:issue:`12805`)
+- ``month_name` and ``weekday_name`` attributes will now return locale aware values (:issue:`12806`)
 
 .. _whatsnew_0211.deprecations:
 

Diff for: pandas/_libs/tslib.pyx

@@ -68,6 +68,7 @@ from khash cimport (
     kh_resize_int64, kh_get_int64)
 
 from .tslibs.parsing import parse_datetime_string
+from .tslibs.strptime import LocaleTime
 
 cimport cython
 
@@ -526,10 +527,15 @@ class Timestamp(_Timestamp):
 
     @property
     def weekday_name(self):
-        cdef dict wdays = {0: 'Monday', 1: 'Tuesday', 2: 'Wednesday',
-                           3: 'Thursday', 4: 'Friday', 5: 'Saturday',
-                           6: 'Sunday'}
-        return wdays[self.weekday()]
+        cdef object locale_time = LocaleTime()
+        cdef dict wdays = dict(enumerate(locale_time.f_weekday))
+        return wdays[self.weekday()].capitalize()
+
+    @property
+    def month_name(self):
+        cdef object locale_time = LocaleTime()
+        cdef dict months = dict(enumerate(locale_time.f_month))
+        return months[self.month].capitalize()
 
     @property
     def dayofyear(self):

Diff for: pandas/_libs/tslibs/fields.pyx

@@ -28,6 +28,7 @@ cimport util
 
 cdef int64_t NPY_NAT = util.get_nat()
 
+from pandas._libs.tslibs.strptime import LocaleTime
 
 def build_field_sarray(ndarray[int64_t] dtindex):
     """
@@ -83,24 +84,31 @@ def get_date_name_field(ndarray[int64_t] dtindex, object field):
         ndarray[object] out
         pandas_datetimestruct dts
         int dow
-
-    _dayname = np.array(
-        ['Monday', 'Tuesday', 'Wednesday', 'Thursday',
-            'Friday', 'Saturday', 'Sunday'],
-        dtype=np.object_)
+        object locale_time = LocaleTime()
 
     count = len(dtindex)
     out = np.empty(count, dtype=object)
 
     if field == 'weekday_name':
+        _dayname = np.array(locale_time.f_weekday, dtype=np.object_)
         for i in range(count):
             if dtindex[i] == NPY_NAT:
                 out[i] = np.nan
                 continue
 
             dt64_to_dtstruct(dtindex[i], &dts)
             dow = dayofweek(dts.year, dts.month, dts.day)
-            out[i] = _dayname[dow]
+            out[i] = _dayname[dow].capitalize()
+        return out
+    elif field == 'month_name':
+        _monthname = np.array(locale_time.f_month, dtype=np.object_)
+        for i in range(count):
+            if dtindex[i] == NPY_NAT:
+                out[i] = np.nan
+                continue
+
+            dt64_to_dtstruct(dtindex[i], &dts)
+            out[i] = _monthname[dts.month].capitalize()
         return out
 
     raise ValueError("Field %s not supported" % field)

Diff for: pandas/core/indexes/datetimes.py

@@ -251,7 +251,7 @@ def _join_i8_wrapper(joinf, **kwargs):
     _bool_ops = ['is_month_start', 'is_month_end',
                  'is_quarter_start', 'is_quarter_end', 'is_year_start',
                  'is_year_end', 'is_leap_year']
-    _object_ops = ['weekday_name', 'freq', 'tz']
+    _object_ops = ['weekday_name', 'month_name', 'freq', 'tz']
     _field_ops = ['year', 'month', 'day', 'hour', 'minute', 'second',
                   'weekofyear', 'week', 'weekday', 'dayofweek',
                   'dayofyear', 'quarter', 'days_in_month',
@@ -1588,6 +1588,11 @@ def _set_freq(self, value):
         'weekday_name',
         "The name of day in a week (ex: Friday)\n\n.. versionadded:: 0.18.1")
 
+    month_name = _field_accessor(
+        'month_name',
+        'month_name',
+        "The name of month in a year (ex: May)\n\n.. versionadded:: 0.21.1")
+
     dayofyear = _field_accessor('dayofyear', 'doy',
                                 "The ordinal day of the year")
     quarter = _field_accessor('quarter', 'q', "The quarter of the date")

Diff for: pandas/tests/indexes/datetimes/test_misc.py

@@ -1,3 +1,6 @@
+import locale
+import calendar
+
 import pytest
 
 import numpy as np
@@ -172,8 +175,9 @@ def test_normalize(self):
 
 class TestDatetime64(object):
 
-    def test_datetimeindex_accessors(self):
-
+    # GH 12806
+    @pytest.mark.parametrize('time_locale', tm.get_locales())
+    def test_datetimeindex_accessors(self, time_locale):
         dti_naive = DatetimeIndex(freq='D', start=datetime(1998, 1, 1),
                                   periods=365)
         # GH 13303
@@ -221,21 +225,12 @@ def test_datetimeindex_accessors(self):
             assert dti.is_year_end[364]
 
             # GH 11128
-            assert dti.weekday_name[4] == u'Monday'
-            assert dti.weekday_name[5] == u'Tuesday'
-            assert dti.weekday_name[6] == u'Wednesday'
-            assert dti.weekday_name[7] == u'Thursday'
-            assert dti.weekday_name[8] == u'Friday'
-            assert dti.weekday_name[9] == u'Saturday'
-            assert dti.weekday_name[10] == u'Sunday'
-
-            assert Timestamp('2016-04-04').weekday_name == u'Monday'
-            assert Timestamp('2016-04-05').weekday_name == u'Tuesday'
-            assert Timestamp('2016-04-06').weekday_name == u'Wednesday'
-            assert Timestamp('2016-04-07').weekday_name == u'Thursday'
-            assert Timestamp('2016-04-08').weekday_name == u'Friday'
-            assert Timestamp('2016-04-09').weekday_name == u'Saturday'
-            assert Timestamp('2016-04-10').weekday_name == u'Sunday'
+            with tm.set_locale(time_locale, locale.LC_TIME):
+                for day, name in zip(range(4, 11), calendar.day_name):
+                    # Test Monday -> Sunday
+                    assert dti.weekday_name[day] == name.capitalize()
+                    date = datetime(2016, 4, day)
+                    assert Timestamp(date).weekday_name == name.capitalize()
 
             assert len(dti.year) == 365
             assert len(dti.month) == 365
@@ -342,6 +337,16 @@ def test_datetimeindex_accessors(self):
         assert dates.weekofyear.tolist() == expected
         assert [d.weekofyear for d in dates] == expected
 
+        # GH 12805
+        with tm.set_locale(time_locale, locale.LC_TIME):
+            dti = DatetimeIndex(freq='M', start='2012', end='2013')
+            result = dti.month_name
+            expected = Index([month.capitalize()
+                              for month in calendar.month_name[1:]])
+            tm.assert_index_equal(result, expected)
+            for date, result in zip(dti, calendar.month_name[1:]):
+                assert date.month_name == result.capitalize()
+
     def test_nanosecond_field(self):
         dti = DatetimeIndex(np.arange(10))
 

Diff for: pandas/tests/series/test_datetime_values.py

@@ -32,7 +32,7 @@ def test_dt_namespace_accessor(self):
         ok_for_dt = DatetimeIndex._datetimelike_ops
         ok_for_dt_methods = ['to_period', 'to_pydatetime', 'tz_localize',
                              'tz_convert', 'normalize', 'strftime', 'round',
-                             'floor', 'ceil', 'weekday_name']
+                             'floor', 'ceil', 'weekday_name', 'month_name']
         ok_for_td = TimedeltaIndex._datetimelike_ops
         ok_for_td_methods = ['components', 'to_pytimedelta', 'total_seconds',
                              'round', 'floor', 'ceil']