Fix wraparound/overflow in date_range

pandas-dev · jreback · Oct 28, 2018 · Feb 17, 2018 · Feb 17, 2018 · Feb 17, 2018
commit 44c3a107c2ea9a2d429daa8422de491a618dbe5f
diff --git a/doc/source/whatsnew/v0.23.0.txt b/doc/source/whatsnew/v0.23.0.txt
@@ -716,7 +716,7 @@ Datetimelike
 - Bug in :class:`Timestamp` and :func:`to_datetime` where a string representing a barely out-of-bounds timestamp would be incorrectly rounded down instead of raising ``OutOfBoundsDatetime`` (:issue:`19382`)
 - Bug in :func:`Timestamp.floor` :func:`DatetimeIndex.floor` where time stamps far in the future and past were not rounded correctly (:issue:`19206`)
 - Bug in :func:`to_datetime` where passing an out-of-bounds datetime with ``errors='coerce'`` and ``utc=True`` would raise ``OutOfBoundsDatetime`` instead of parsing to ``NaT`` (:issue:`19612`)
--
+- Bug in :func:`date_range` where dates sufficiently far in the future could wrap around to the past instead of raising ``OutOfBoundsDatetime`` (:issue:``)
 
 Timezones
 ^^^^^^^^^

diff --git a/pandas/core/indexes/datetimes.py b/pandas/core/indexes/datetimes.py
@@ -2137,11 +2137,30 @@ def _generate_regular_range(start, end, periods, offset):
             tz = start.tz
         elif start is not None:
             b = Timestamp(start).value
-            e = b + np.int64(periods) * stride
+            try:
+                with np.errstate(over='raise'):
+                    # raise instead of incorrectly wrapping around
+                    e = b + np.int64(periods) * stride
+            except (FloatingPointError, OverflowError):
+                raise libts.OutOfBoundsDatetime('Cannot generate range with '
+                                                'start={start} and '
+                                                'periods={periods}'
+                                                .format(start=start,
+                                                        periods=periods))
+
             tz = start.tz
         elif end is not None:
             e = Timestamp(end).value + stride
-            b = e - np.int64(periods) * stride
+            try:
+                with np.errstate(over='raise'):
+                    # raise instead of incorrectly wrapping around
+                    b = e - np.int64(periods) * stride
+            except (FloatingPointError, OverflowError):
+                raise libts.OutOfBoundsDatetime('Cannot generate range with '
+                                                'start={start} and '
+                                                'periods={periods}'
+                                                .format(start=start,
+                                                        periods=periods))
             tz = end.tz
         else:
             raise ValueError("at least 'start' or 'end' should be specified "

diff --git a/pandas/tests/indexes/datetimes/test_date_range.py b/pandas/tests/indexes/datetimes/test_date_range.py
@@ -13,6 +13,7 @@
 import pandas.util.testing as tm
 import pandas.util._test_decorators as td
 from pandas import compat
+from pandas.errors import OutOfBoundsDatetime
 from pandas import date_range, bdate_range, offsets, DatetimeIndex, Timestamp
 from pandas.tseries.offsets import (generate_range, CDay, BDay, DateOffset,
                                     MonthEnd, prefix_mapping)
@@ -78,6 +79,11 @@ def test_date_range_timestamp_equiv_preserve_frequency(self):
 
 
 class TestDateRanges(TestData):
+    def test_date_range_out_of_bounds(self):
+        with pytest.raises(OutOfBoundsDatetime):
+            date_range('2016-01-01', periods=100000, freq='D')
+        with pytest.raises(OutOfBoundsDatetime):
+            date_range(end='1763-10-12', periods=100000, freq='D')
 
     def test_date_range_gen_error(self):
         rng = date_range('1/1/2000 00:00', '1/1/2000 00:18', freq='5min')