arrays/period: allow parsing of PeriodDtype columns from read_csv

doc/source/whatsnew/v0.25.0.rst

@@ -1103,6 +1103,7 @@ I/O
 - Bug in :meth:`read_hdf` where reading a timezone aware :class:`DatetimeIndex` would raise a ``TypeError`` (:issue:`11926`)
 - Bug in :meth:`to_msgpack` and :meth:`read_msgpack` which would raise a ``ValueError`` rather than a ``FileNotFoundError`` for an invalid path (:issue:`27160`)
 - Fixed bug in :meth:`DataFrame.to_parquet` which would raise a ``ValueError`` when the dataframe had no columns (:issue:`27339`)
+- Allow parsing of :class:`PeriodDtype` columns when using :func:`read_csv` (:issue:`26934`)
 
 Plotting
 ^^^^^^^^

pandas/core/arrays/period.py

@@ -253,6 +253,10 @@ def _from_sequence(
         ordinals = libperiod.extract_ordinals(periods, freq)
         return cls(ordinals, freq=freq)
 
+    @classmethod
+    def _from_sequence_of_strings(cls, strings, dtype=None, copy=False):
+        return cls._from_sequence(strings, dtype, copy)
+
     @classmethod
     def _from_datetime64(cls, data, freq, tz=None):
         """

pandas/tests/extension/test_period.py

@@ -158,6 +158,4 @@ class TestPrinting(BasePeriodTests, base.BasePrintingTests):
 class TestParsing(BasePeriodTests, base.BaseParsingTests):
     @pytest.mark.parametrize("engine", ["c", "python"])
     def test_EA_types(self, engine, data):
-        expected_msg = r".*must implement _from_sequence_of_strings.*"
-        with pytest.raises(NotImplementedError, match=expected_msg):
-            super().test_EA_types(engine, data)
+        super().test_EA_types(engine, data)