done

lib/python3.11/site-packages/pandas/tests/indexes/period/test_monotonic.py

@@ -0,0 +1,42 @@
+from pandas import (
+    Period,
+    PeriodIndex,
+)
+
+
+def test_is_monotonic_increasing():
+    # GH#17717
+    p0 = Period("2017-09-01")
+    p1 = Period("2017-09-02")
+    p2 = Period("2017-09-03")
+
+    idx_inc0 = PeriodIndex([p0, p1, p2])
+    idx_inc1 = PeriodIndex([p0, p1, p1])
+    idx_dec0 = PeriodIndex([p2, p1, p0])
+    idx_dec1 = PeriodIndex([p2, p1, p1])
+    idx = PeriodIndex([p1, p2, p0])
+
+    assert idx_inc0.is_monotonic_increasing is True
+    assert idx_inc1.is_monotonic_increasing is True
+    assert idx_dec0.is_monotonic_increasing is False
+    assert idx_dec1.is_monotonic_increasing is False
+    assert idx.is_monotonic_increasing is False
+
+
+def test_is_monotonic_decreasing():
+    # GH#17717
+    p0 = Period("2017-09-01")
+    p1 = Period("2017-09-02")
+    p2 = Period("2017-09-03")
+
+    idx_inc0 = PeriodIndex([p0, p1, p2])
+    idx_inc1 = PeriodIndex([p0, p1, p1])
+    idx_dec0 = PeriodIndex([p2, p1, p0])
+    idx_dec1 = PeriodIndex([p2, p1, p1])
+    idx = PeriodIndex([p1, p2, p0])
+
+    assert idx_inc0.is_monotonic_decreasing is False
+    assert idx_inc1.is_monotonic_decreasing is False
+    assert idx_dec0.is_monotonic_decreasing is True
+    assert idx_dec1.is_monotonic_decreasing is True
+    assert idx.is_monotonic_decreasing is False