BUG: PeriodIndex.__new__ with keyword mismatch (#55961)

* BUG: PeriodIndex.__new__ with keyword mismatch

* GH refs

doc/source/whatsnew/v2.2.0.rst

@@ -420,6 +420,7 @@ I/O
 
 Period
 ^^^^^^
+- Bug in :class:`PeriodIndex` construction when more than one of ``data``, ``ordinal`` and ``**fields`` are passed failing to raise ``ValueError`` (:issue:`55961`)
 - Bug in :class:`Period` addition silently wrapping around instead of raising ``OverflowError`` (:issue:`55503`)
 - Bug in casting from :class:`PeriodDtype` with ``astype`` to ``datetime64`` or :class:`DatetimeTZDtype` with non-nanosecond unit incorrectly returning with nanosecond unit (:issue:`55958`)
 -

pandas/core/indexes/period.py

@@ -249,6 +249,11 @@ def __new__(
 
             dtype = PeriodDtype(freq)
             data = PeriodArray(data, dtype=dtype)
+        elif fields:
+            if data is not None:
+                raise ValueError("Cannot pass both data and fields")
+            raise ValueError("Cannot pass both ordinal and fields")
+
         else:
             freq = validate_dtype_freq(dtype, freq)
 
@@ -261,10 +266,11 @@ def __new__(
                 data = data.asfreq(freq)
 
             if data is None and ordinal is not None:
-                # we strangely ignore `ordinal` if data is passed.
                 ordinal = np.asarray(ordinal, dtype=np.int64)
                 dtype = PeriodDtype(freq)
                 data = PeriodArray(ordinal, dtype=dtype)
+            elif data is not None and ordinal is not None:
+                raise ValueError("Cannot pass both data and ordinal")
             else:
                 # don't pass copy here, since we copy later.
                 data = period_array(data=data, freq=freq)

pandas/tests/indexes/period/test_constructors.py

@@ -20,6 +20,22 @@
 
 
 class TestPeriodIndex:
+    def test_keyword_mismatch(self):
+        # GH#55961 we should get exactly one of data/ordinals/**fields
+        per = Period("2016-01-01", "D")
+
+        err_msg1 = "Cannot pass both data and ordinal"
+        with pytest.raises(ValueError, match=err_msg1):
+            PeriodIndex(data=[per], ordinal=[per.ordinal], freq=per.freq)
+
+        err_msg2 = "Cannot pass both data and fields"
+        with pytest.raises(ValueError, match=err_msg2):
+            PeriodIndex(data=[per], year=[per.year], freq=per.freq)
+
+        err_msg3 = "Cannot pass both ordinal and fields"
+        with pytest.raises(ValueError, match=err_msg3):
+            PeriodIndex(ordinal=[per.ordinal], year=[per.year], freq=per.freq)
+
     def test_construction_base_constructor(self):
         # GH 13664
         arr = [Period("2011-01", freq="M"), NaT, Period("2011-03", freq="M")]