Take 2

Author: TomAugspurger

pandas/core/frame.py

@@ -4908,8 +4908,7 @@ def _combine_match_index(self, other, func, level=None):
             return ops.dispatch_to_series(left, right, func)
         else:
             # fastpath --> operate directly on values
-            with np.errstate(all="ignore"):
-                new_data = func(left.values.T, right.values).T
+            new_data = func(left.values.T, right.values).T
             return self._constructor(new_data,
                                      index=left.index, columns=self.columns,
                                      copy=False)

pandas/core/ops.py

@@ -138,6 +138,15 @@ def maybe_upcast_for_op(obj):
     return obj
 
 
+def silent_truediv(x, y):
+    """Like operator.truediv, but with NumPy warnings silenced."""
+    with np.errstate(all="ignore"):
+        return operator.truediv(x ,y)
+
+
+silent_truediv.__name__ = 'truediv'
+silent_truediv.__doc__ = operator.truediv.__doc__
+
 # -----------------------------------------------------------------------------
 # Reversed Operations not available in the stdlib operator module.
 # Defining these instead of using lambdas allows us to reference them by name.
@@ -159,7 +168,7 @@ def rdiv(left, right):
 
 
 def rtruediv(left, right):
-    return right / left
+    return silent_truediv(right, left)
 
 
 def rfloordiv(left, right):
@@ -339,7 +348,7 @@ def _get_opstr(op, cls):
             rmul: '*',
             operator.sub: '-',
             rsub: '-',
-            operator.truediv: '/',
+            silent_truediv: '/',
             rtruediv: '/',
             operator.floordiv: '//',
             rfloordiv: '//',
@@ -1012,7 +1021,7 @@ def _create_methods(cls, arith_method, comp_method, bool_method, special):
         radd=arith_method(cls, radd, special),
         sub=arith_method(cls, operator.sub, special),
         mul=arith_method(cls, operator.mul, special),
-        truediv=arith_method(cls, operator.truediv, special),
+        truediv=arith_method(cls, silent_truediv, special),
         floordiv=arith_method(cls, operator.floordiv, special),
         # Causes a floating point exception in the tests when numexpr enabled,
         # so for now no speedup

pandas/tests/frame/test_operators.py

@@ -1030,3 +1030,9 @@ def test_alignment_non_pandas(self):
             align(df, val, 'index')
         with pytest.raises(ValueError):
             align(df, val, 'columns')
+
+    def test_no_warning(self, all_arithmetic_operators):
+        df = pd.DataFrame({"A": [0.,0.], "B": [0., None]})
+        b = df['B']
+        with tm.assert_produces_warning(None):
+            getattr(df, all_arithmetic_operators)(b, 0)