use tzinfo=object to accept None as a default parameter

Author: jreback

doc/source/whatsnew/v0.20.0.txt

@@ -416,7 +416,7 @@ Performance Improvements
 Bug Fixes
 ~~~~~~~~~
 
-- Bug in ``Timestamp.replace`` exception ValueError raised when wrong argument name given, should be TypeError (:issue:`15240`)
+- Bug in ``Timestamp.replace`` now raises ``TypeError`` when incorrect argument names are given; previously this raised ``ValueError`` (:issue:`15240`)
 - Bug in ``Index`` power operations with reversed operands (:issue:`14973`)
 - Bug in ``TimedeltaIndex`` addition where overflow was being allowed without error (:issue:`14816`)
 - Bug in ``TimedeltaIndex`` raising a ``ValueError`` when boolean indexing with ``loc`` (:issue:`14946`)

pandas/tseries/tests/test_timezones.py

@@ -826,7 +826,6 @@ def test_date_range_span_dst_transition(self):
     def test_convert_datetime_list(self):
         dr = date_range('2012-06-02', periods=10,
                         tz=self.tzstr('US/Eastern'), name='foo')
-
         dr2 = DatetimeIndex(list(dr), name='foo')
         self.assert_index_equal(dr, dr2)
         self.assertEqual(dr.tz, dr2.tz)

pandas/tslib.pyx

@@ -652,7 +652,7 @@ class Timestamp(_Timestamp):
 
     def replace(self, year=None, month=None, day=None,
                 hour=None, minute=None, second=None, microsecond=None, nanosecond=None,
-                tzinfo=None):
+                tzinfo=object, fold=0):
         """
         implements datetime.replace, handles nanoseconds
 
@@ -667,6 +667,8 @@ class Timestamp(_Timestamp):
         microsecond : int, optional
         nanosecond: int, optional
         tzinfo : tz-convertible, optional
+        fold : int, optional, default is 0
+            added in 3.6, NotImplemented
 
         Returns
         -------
@@ -713,7 +715,7 @@ class Timestamp(_Timestamp):
             dts.us = validate('microsecond', microsecond)
         if nanosecond is not None:
             dts.ps = validate('nanosecond', nanosecond) * 1000
-        if tzinfo is not None:
+        if tzinfo is not object:
             _tzinfo = tzinfo
 
         # reconstruct & check bounds
@@ -726,7 +728,6 @@ class Timestamp(_Timestamp):
             value = tz_convert_single(value, _tzinfo, 'UTC')
 
         result = create_timestamp_from_ts(value, dts, _tzinfo, self.freq)
-
         return result
 
     def isoformat(self, sep='T'):