Added support for __divmod__ and __rdivmod__, with a basic unit test.

theano/tensor/basic.py

@@ -2905,6 +2905,9 @@ def div_proxy(x, y):
         as_tensor_variable(y).dtype in discrete_dtypes))
     return f(x, y)
 
+def divmod(x, y):
+    """elementvise divmod, using floor_div and mod_check"""
+    return floor_div(x, y), mod_check(x, y)
 
 @_scal_elemwise_with_nfunc('add', 2, 1)
 def add(a, *other_terms):

theano/tensor/tests/test_basic.py

@@ -6113,7 +6113,7 @@ def test_len():
 def test_mod():
     """
     We add this test as not all language and C implementation give the same
-    signe to the result. This check that the c_code of `Mod` is implemented
+    sign to the result. This check that the c_code of `Mod` is implemented
     as Python. That is what we want.
     """
     x, y = fscalars('xy')
@@ -6126,6 +6126,23 @@ def test_mod():
         assert fn(a, b) == a % b, (a,)
 
 
+def test_divmod():
+    """
+    Confirm that divmod is equivalent to the python version.
+    """
+    x, y = fscalars('xy')
+    d, r = divmod(x, y)
+    fn = gof.DualLinker().accept(
+            gof.FunctionGraph([x, y], [d, r])).make_function()
+    for a, b in ((0, 1), (1, 1), (0, -1), (1, -1), (-1, -1),
+                (1, 2), (-1, 2), (1, -2), (-1, -2),
+                (5, 3), (-5, 3), (5, -3), (-5, -3)
+                ):
+        d_v, r_v = fn(a, b)
+        d_vp, r_vp = divmod(a, b)
+        assert d_v == d_vp and r_v == r_vp, (a,)
+
+
 def test_mod_compile():
     """
     This test generate an Elemwise of Composite as:

theano/tensor/var.py

@@ -190,6 +190,9 @@ class _tensor_py_operators:
         except (NotImplementedError, AsTensorError):
             return NotImplemented
 
+    def __divmod__(self, other):
+        return theano.tensor.basic.divmod(self, other)
+
     def __truediv__(self, other):
         return theano.tensor.basic.true_div(self, other)
 
@@ -235,6 +238,10 @@ class _tensor_py_operators:
     def __rmod__(self, other):
         return theano.tensor.basic.mod(other, self)
 
+    def __rdivmod__(self, other):
+        return theano.tensor.basic.divmod(other, self)
+
+
     def __rpow__(self, other):
         return theano.tensor.basic.pow(other, self)