Merge branch 'timestamp_min_max' of https://github.com/SleepingPills/pandas into SleepingPills-timestamp_min_max

Conflicts:
	RELEASE.rst
	doc/source/v0.12.0.txt

Author: jreback

doc/source/gotchas.rst

@@ -271,9 +271,10 @@ can be represented using a 64-bit integer is limited to approximately 584 years:
 
 .. ipython:: python
 
-   begin = Timestamp(-9223285636854775809L)
+   begin = Timestamp.min
    begin
-   end = Timestamp(np.iinfo(np.int64).max)
+
+   end = Timestamp.max
    end
 
 If you need to represent time series data outside the nanosecond timespan, use

doc/source/release.rst

@@ -101,6 +101,8 @@ pandas 0.12
   - ``read_csv`` will now throw a more informative error message when a file
     contains no columns, e.g., all newline characters
   - Added ``layout`` keyword to DataFrame.hist() for more customizable layout (:issue:`4050`)
+  - Timestamp.min and Timestamp.max now represent valid Timestamp instances instead
+    of the default datetime.min and datetime.max (respectively), thanks @SleepingPills
 
 **API Changes**
 

doc/source/v0.12.0.txt

@@ -337,9 +337,13 @@ Other Enhancements
        dff.groupby('B').filter(lambda x: len(x) > 2, dropna=False)
 
   - Series and DataFrame hist methods now take a ``figsize`` argument (:issue:`3834`)
+
   - DatetimeIndexes no longer try to convert mixed-integer indexes during join
     operations (:issue:`3877`)
 
+  - Timestamp.min and Timestamp.max now represent valid Timestamp instances instead
+    of the default datetime.min and datetime.max (respectively), thanks @SleepingPills
+
 Experimental Features
 ~~~~~~~~~~~~~~~~~~~~~
 

pandas/tests/test_tseries.py

@@ -2,7 +2,7 @@
 
 from numpy import nan
 import numpy as np
-from pandas import Index, isnull
+from pandas import Index, isnull, Timestamp
 from pandas.util.testing import assert_almost_equal
 import pandas.util.testing as common
 import pandas.lib as lib
@@ -683,6 +683,22 @@ def test_int_index(self):
         expected = arr.sum(1)
         assert_almost_equal(result, expected)
 
+
+class TestTsUtil(unittest.TestCase):
+    def test_min_valid(self):
+        # Ensure that Timestamp.min is a valid Timestamp
+        Timestamp(Timestamp.min)
+
+    def test_max_valid(self):
+        # Ensure that Timestamp.max is a valid Timestamp
+        Timestamp(Timestamp.max)
+
+    def test_to_datetime_bijective(self):
+        # Ensure that converting to datetime and back only loses precision
+        # by going from nanoseconds to microseconds.
+        self.assertEqual(Timestamp(Timestamp.max.to_pydatetime()).value/1000, Timestamp.max.value/1000)
+        self.assertEqual(Timestamp(Timestamp.min.to_pydatetime()).value/1000, Timestamp.min.value/1000)
+
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=[__file__, '-vvs', '-x', '--pdb', '--pdb-failure'],

pandas/tslib.pyx

@@ -388,6 +388,15 @@ cpdef object get_value_box(ndarray arr, object loc):
         return util.get_value_1d(arr, i)
 
 
+# Add the min and max fields at the class level
+# These are defined as magic numbers due to strange
+# wraparound behavior when using the true int64 lower boundary
+cdef int64_t _NS_LOWER_BOUND = -9223285636854775000LL
+cdef int64_t _NS_UPPER_BOUND = 9223372036854775807LL
+Timestamp.min = Timestamp(_NS_LOWER_BOUND)
+Timestamp.max = Timestamp(_NS_UPPER_BOUND)
+
+
 #----------------------------------------------------------------------
 # Frequency inference
 
@@ -770,8 +779,6 @@ cdef inline object _get_zone(object tz):
         except AttributeError:
             return tz
 
-# cdef int64_t _NS_LOWER_BOUND = -9223285636854775809LL
-# cdef int64_t _NS_UPPER_BOUND = -9223372036854775807LL
 
 cdef inline _check_dts_bounds(int64_t value, pandas_datetimestruct *dts):
     cdef pandas_datetimestruct dts2