FMT: trim redundant freqstr from PeriodIndex __repr__ (#41653)

Author: jbrockmendel

pandas/core/arrays/datetimes.py

@@ -1119,14 +1119,14 @@ def to_period(self, freq=None) -> PeriodArray:
         ...                                         "2000-08-31 00:00:00"]))
         >>> df.index.to_period("M")
         PeriodIndex(['2000-03', '2000-05', '2000-08'],
-                    dtype='period[M]', freq='M')
+                    dtype='period[M]')
 
         Infer the daily frequency
 
         >>> idx = pd.date_range("2017-01-01", periods=2)
         >>> idx.to_period()
         PeriodIndex(['2017-01-01', '2017-01-02'],
-                    dtype='period[D]', freq='D')
+                    dtype='period[D]')
         """
         from pandas.core.arrays import PeriodArray
 

pandas/core/arrays/period.py

@@ -564,15 +564,15 @@ def asfreq(self, freq=None, how: str = "E") -> PeriodArray:
         >>> pidx = pd.period_range('2010-01-01', '2015-01-01', freq='A')
         >>> pidx
         PeriodIndex(['2010', '2011', '2012', '2013', '2014', '2015'],
-        dtype='period[A-DEC]', freq='A-DEC')
+        dtype='period[A-DEC]')
 
         >>> pidx.asfreq('M')
         PeriodIndex(['2010-12', '2011-12', '2012-12', '2013-12', '2014-12',
-        '2015-12'], dtype='period[M]', freq='M')
+        '2015-12'], dtype='period[M]')
 
         >>> pidx.asfreq('M', how='S')
         PeriodIndex(['2010-01', '2011-01', '2012-01', '2013-01', '2014-01',
-        '2015-01'], dtype='period[M]', freq='M')
+        '2015-01'], dtype='period[M]')
         """
         how = libperiod.validate_end_alias(how)
 

pandas/core/indexes/period.py

@@ -153,11 +153,11 @@ class PeriodIndex(DatetimeIndexOpsMixin):
     --------
     >>> idx = pd.PeriodIndex(year=[2000, 2002], quarter=[1, 3])
     >>> idx
-    PeriodIndex(['2000Q1', '2002Q3'], dtype='period[Q-DEC]', freq='Q-DEC')
+    PeriodIndex(['2000Q1', '2002Q3'], dtype='period[Q-DEC]')
     """
 
     _typ = "periodindex"
-    _attributes = ["name", "freq"]
+    _attributes = ["name"]
 
     # define my properties & methods for delegation
     _is_numeric_dtype = False
@@ -636,7 +636,7 @@ def period_range(
     PeriodIndex(['2017-01', '2017-02', '2017-03', '2017-04', '2017-05', '2017-06',
              '2017-07', '2017-08', '2017-09', '2017-10', '2017-11', '2017-12',
              '2018-01'],
-            dtype='period[M]', freq='M')
+            dtype='period[M]')
 
     If ``start`` or ``end`` are ``Period`` objects, they will be used as anchor
     endpoints for a ``PeriodIndex`` with frequency matching that of the
@@ -645,7 +645,7 @@ def period_range(
     >>> pd.period_range(start=pd.Period('2017Q1', freq='Q'),
     ...                 end=pd.Period('2017Q2', freq='Q'), freq='M')
     PeriodIndex(['2017-03', '2017-04', '2017-05', '2017-06'],
-                dtype='period[M]', freq='M')
+                dtype='period[M]')
     """
     if com.count_not_none(start, end, periods) != 2:
         raise ValueError(

pandas/tests/indexes/datetimelike.py

@@ -44,7 +44,9 @@ def test_str(self, simple_index):
         if hasattr(idx, "tz"):
             if idx.tz is not None:
                 assert idx.tz in str(idx)
-        if hasattr(idx, "freq"):
+        if isinstance(idx, pd.PeriodIndex):
+            assert f"dtype='period[{idx.freqstr}]'" in str(idx)
+        else:
             assert f"freq='{idx.freqstr}'" in str(idx)
 
     def test_view(self, simple_index):

pandas/tests/indexes/period/test_formats.py

@@ -62,40 +62,31 @@ def test_representation(self, method):
         idx9 = pd.period_range("2013Q1", periods=3, freq="Q")
         idx10 = PeriodIndex(["2011-01-01", "2011-02-01"], freq="3D")
 
-        exp1 = "PeriodIndex([], dtype='period[D]', freq='D')"
+        exp1 = "PeriodIndex([], dtype='period[D]')"
 
-        exp2 = "PeriodIndex(['2011-01-01'], dtype='period[D]', freq='D')"
+        exp2 = "PeriodIndex(['2011-01-01'], dtype='period[D]')"
 
-        exp3 = "PeriodIndex(['2011-01-01', '2011-01-02'], dtype='period[D]', freq='D')"
+        exp3 = "PeriodIndex(['2011-01-01', '2011-01-02'], dtype='period[D]')"
 
         exp4 = (
             "PeriodIndex(['2011-01-01', '2011-01-02', '2011-01-03'], "
-            "dtype='period[D]', freq='D')"
+            "dtype='period[D]')"
         )
 
-        exp5 = (
-            "PeriodIndex(['2011', '2012', '2013'], dtype='period[A-DEC]', "
-            "freq='A-DEC')"
-        )
+        exp5 = "PeriodIndex(['2011', '2012', '2013'], dtype='period[A-DEC]')"
 
         exp6 = (
             "PeriodIndex(['2011-01-01 09:00', '2012-02-01 10:00', 'NaT'], "
-            "dtype='period[H]', freq='H')"
+            "dtype='period[H]')"
         )
 
-        exp7 = "PeriodIndex(['2013Q1'], dtype='period[Q-DEC]', freq='Q-DEC')"
+        exp7 = "PeriodIndex(['2013Q1'], dtype='period[Q-DEC]')"
 
-        exp8 = "PeriodIndex(['2013Q1', '2013Q2'], dtype='period[Q-DEC]', freq='Q-DEC')"
+        exp8 = "PeriodIndex(['2013Q1', '2013Q2'], dtype='period[Q-DEC]')"
 
-        exp9 = (
-            "PeriodIndex(['2013Q1', '2013Q2', '2013Q3'], "
-            "dtype='period[Q-DEC]', freq='Q-DEC')"
-        )
+        exp9 = "PeriodIndex(['2013Q1', '2013Q2', '2013Q3'], dtype='period[Q-DEC]')"
 
-        exp10 = (
-            "PeriodIndex(['2011-01-01', '2011-02-01'], "
-            "dtype='period[3D]', freq='3D')"
-        )
+        exp10 = "PeriodIndex(['2011-01-01', '2011-02-01'], dtype='period[3D]')"
 
         for idx, expected in zip(
             [idx1, idx2, idx3, idx4, idx5, idx6, idx7, idx8, idx9, idx10],