ENH: set __module__ for objects in pandas Scalars API

Author: YinonLensor

pandas/_libs/tslibs/period.pyx

@@ -115,6 +115,8 @@ from pandas._libs.tslibs.offsets import (
     BDay,
 )
 
+from pandas.util._decorators import set_module
+
 cdef:
     enum:
         INT32_MIN = -2_147_483_648LL
@@ -2662,6 +2664,7 @@ cdef class _Period(PeriodMixin):
         return period_format(self.ordinal, base, fmt)
 
 
+@set_module("pandas")
 class Period(_Period):
     """
     Represents a period of time.

pandas/_libs/tslibs/timedeltas.pyx

@@ -1,6 +1,7 @@
 import collections
 import warnings
 
+from pandas.util._decorators import set_module
 from pandas.util._exceptions import find_stack_level
 
 cimport cython
@@ -1771,7 +1772,7 @@ cdef class _Timedelta(timedelta):
 
 # Python front end to C extension type _Timedelta
 # This serves as the box for timedelta64
-
+@set_module("pandas")
 class Timedelta(_Timedelta):
     """
     Represents a duration, the difference between two dates or times.

pandas/_libs/tslibs/timestamps.pyx

@@ -50,6 +50,7 @@ import datetime as dt
 from pandas._libs.tslibs cimport ccalendar
 from pandas._libs.tslibs.base cimport ABCTimestamp
 
+from pandas.util._decorators import set_module
 from pandas.util._exceptions import find_stack_level
 
 from pandas._libs.tslibs.conversion cimport (
@@ -1263,7 +1264,7 @@ cdef class _Timestamp(ABCTimestamp):
 # Python front end to C extension type _Timestamp
 # This serves as the box for datetime64
 
-
+@set_module("pandas")
 class Timestamp(_Timestamp):
     """
     Pandas replacement for python datetime.datetime object.

pandas/tests/api/test_api.py

@@ -405,3 +405,6 @@ def test_pandas_array_alias():
 
 def test_set_module():
     assert pd.DataFrame.__module__ == "pandas"
+    assert pd.Period.__module__ == "pandas"
+    assert pd.Timestamp.__module__ == "pandas"
+    assert pd.Timedelta.__module__ == "pandas"