implement+test tick rdiv

pandas-dev · jreback · Feb 1, 2019 · Jan 18, 2019 · Jan 18, 2019 · Jan 18, 2019
commit 2f02ae1016ed1af9840dfb044846af627f17ce8b
diff --git a/pandas/_libs/tslibs/offsets.pyx b/pandas/_libs/tslibs/offsets.pyx
@@ -533,12 +533,20 @@ class _Tick(object):
     can do isinstance checks on _Tick and avoid importing tseries.offsets
     """
 
+    # ensure that reversed-ops with numpy scalars return NotImplemented
+    __array_priority__ = 1000
+
     def __truediv__(self, other):
         result = self.delta.__truediv__(other)
         return _wrap_timedelta_result(result)
 
+    def __rtruediv__(self, other):
+        result = self.delta.__rtruediv__(other)
+        return _wrap_timedelta_result(result)
+
     if PY2:
         __div__ = __truediv__
+        __rdiv__ = __rtruediv__
 
 
 # ----------------------------------------------------------------------

diff --git a/pandas/tests/tseries/offsets/test_ticks.py b/pandas/tests/tseries/offsets/test_ticks.py
@@ -15,6 +15,8 @@
 from pandas.tseries import offsets
 from pandas.tseries.offsets import Hour, Micro, Milli, Minute, Nano, Second
 
+import pandas.util.testing as tm
+
 from .common import assert_offset_equal
 
 # ---------------------------------------------------------------------
@@ -262,6 +264,28 @@ def test_tick_division(cls):
         assert result.delta == off.delta / .001
 
 
+@pytest.mark.parametrize('cls', tick_classes)
+def test_tick_rdiv(cls):
+    off = cls(10)
+    delta = off.delta
+    td64 = delta.to_timedelta64()
+
+    with pytest.raises(TypeError):
+        2 / off
+    with pytest.raises(TypeError):
+        2.0 / off
+
+    assert (td64 * 2.5) / off == 2.5
+
+    if cls is not Nano:
+        # skip pytimedelta for Nano since it gets dropped
+        assert (delta.to_pytimedelta() * 2) / off == 2
+
+    result = np.array([2 * td64, td64]) / off
+    expected = np.array([2., 1.])
+    tm.assert_numpy_array_equal(result, expected)
+
+
 @pytest.mark.parametrize('cls1', tick_classes)
 @pytest.mark.parametrize('cls2', tick_classes)
 def test_tick_zero(cls1, cls2):