Merge pull request #3138 from jreback/GH3042

BUG: GH3042 Timestamp now supports classmethod fromordinal similar to datetimes

Author: jreback

RELEASE.rst

@@ -113,7 +113,6 @@ pandas 0.11.0
         df = DataFrame(dict(A = ts))
         df['2001']
 
-
 **API Changes**
 
   - Do not automatically upcast numeric specified dtypes to ``int64`` or
@@ -220,7 +219,10 @@ pandas 0.11.0
   - Allow selection in an *unordered* timeseries to work similary 
     to an *ordered* timeseries (GH2437_).
   - Fix implemented ``.xs`` when called with ``axes=1`` and a level parameter (GH2903_)
+  - Timestamp now supports the class method fromordinal similar to datetimes (GH3042_)
 
+.. _GH622: https://github.com/pydata/pandas/issues/622
+.. _GH797: https://github.com/pydata/pandas/issues/797
 .. _GH2758: https://github.com/pydata/pandas/issues/2758
 .. _GH2809: https://github.com/pydata/pandas/issues/2809
 .. _GH2810: https://github.com/pydata/pandas/issues/2810
@@ -236,8 +238,6 @@ pandas 0.11.0
 .. _GH2807: https://github.com/pydata/pandas/issues/2807
 .. _GH2918: https://github.com/pydata/pandas/issues/2918
 .. _GH3011: https://github.com/pydata/pandas/issues/3011
-.. _GH622: https://github.com/pydata/pandas/issues/622
-.. _GH797: https://github.com/pydata/pandas/issues/797
 .. _GH2681: https://github.com/pydata/pandas/issues/2681
 .. _GH2719: https://github.com/pydata/pandas/issues/2719
 .. _GH2746: https://github.com/pydata/pandas/issues/2746
@@ -267,19 +267,20 @@ pandas 0.11.0
 .. _GH2967: https://github.com/pydata/pandas/issues/2967
 .. _GH2982: https://github.com/pydata/pandas/issues/2982
 .. _GH2989: https://github.com/pydata/pandas/issues/2989
+.. _GH2993: https://github.com/pydata/pandas/issues/2993
 .. _GH3002: https://github.com/pydata/pandas/issues/3002
 .. _GH3010: https://github.com/pydata/pandas/issues/3010
 .. _GH3012: https://github.com/pydata/pandas/issues/3012
 .. _GH3029: https://github.com/pydata/pandas/issues/3029
 .. _GH3037: https://github.com/pydata/pandas/issues/3037
 .. _GH3041: https://github.com/pydata/pandas/issues/3041
+.. _GH3042: https://github.com/pydata/pandas/issues/3042
 .. _GH3053: https://github.com/pydata/pandas/issues/3053
+.. _GH3070: https://github.com/pydata/pandas/issues/3070
 .. _GH3076: https://github.com/pydata/pandas/issues/3076
 .. _GH3063: https://github.com/pydata/pandas/issues/3063
 .. _GH3059: https://github.com/pydata/pandas/issues/3059
-.. _GH2993: https://github.com/pydata/pandas/issues/2993
 .. _GH3115: https://github.com/pydata/pandas/issues/3115
-.. _GH3070: https://github.com/pydata/pandas/issues/3070
 .. _GH3130: https://github.com/pydata/pandas/issues/3130
 
 pandas 0.10.1

pandas/tseries/tests/test_timeseries.py

@@ -1262,6 +1262,19 @@ def test_timestamp_repr(self):
         result = repr(stamp)
         self.assert_(iso8601 in result)
 
+    def test_timestamp_from_ordinal(self):
+
+        # GH 3042
+        dt = datetime(2011, 4, 16, 0, 0)
+        ts = Timestamp.fromordinal(dt.toordinal())
+        self.assert_(ts.to_pydatetime() == dt)
+
+        # with a tzinfo
+        stamp = Timestamp('2011-4-16', tz='US/Eastern')
+        dt_tz = stamp.to_pydatetime()
+        ts = Timestamp.fromordinal(dt_tz.toordinal(),tz='US/Eastern')
+        self.assert_(ts.to_pydatetime() == dt_tz)
+
     def test_datetimeindex_integers_shift(self):
         rng = date_range('1/1/2000', periods=20)
 

pandas/tslib.pyx

@@ -120,6 +120,12 @@ def _is_fixed_offset(tz):
 # This serves as the box for datetime64
 class Timestamp(_Timestamp):
 
+    @classmethod
+    def fromordinal(cls, ordinal, offset=None, tz=None):
+        """ passed an ordinal, translate and convert to a ts
+            note: by definition there cannot be any tz info on the ordinal itself """
+        return cls(datetime.fromordinal(ordinal),offset=offset,tz=tz)
+
     def __new__(cls, object ts_input, object offset=None, tz=None):
         cdef _TSObject ts
         cdef _Timestamp ts_base