* Changed compute_test_value options to ('off','ignore','warn','err')

theano/configdefaults.py

@@ -237,5 +237,5 @@ AddConfigVar('warn.sum_div_dimshuffle_bug',
 
 AddConfigVar('compute_test_value',
         "If 'True', Theano will run each op at graph build time, using Constants, SharedVariables and the tag 'test_value' as inputs to the function. This helps the user track down problems in the graph before it gets optimized.",
-        EnumStr('False', 'True', 'warn', 'err'),
+        EnumStr('off', 'ignore', 'warn', 'raise'),
         in_c_key=False)

theano/gof/op.py

@@ -10,6 +10,7 @@ from theano import config
 import graph
 import numpy
 import utils
+import warnings
 import logging
 from theano import config
 from env import Env
@@ -327,7 +328,7 @@ class PureOp(object):
         node = self.make_node(*inputs, **kwargs)
         self.add_tag_trace(node)
 
-        if config.compute_test_value != 'False':
+        if config.compute_test_value != 'off':
             # avoid circular import
             from theano.compile.sharedvalue import SharedVariable
             run_perform = True
@@ -345,14 +346,15 @@ class PureOp(object):
                 else:
                     # no test-value was specified, act accordingly
                     if config.compute_test_value == 'warn':
-                        # TODO: use warnings.warn, http://docs.python.org/library/warnings.html#warnings.warn
-                        print >>sys.stderr, ('Warning, Cannot compute test value: input %i (%s) of Op %s missing default value' % (i, ins, node))
+                        warnings.warn('Warning, Cannot compute test value: input %i (%s) of Op %s missing default value' % (i, ins, node), stacklevel=2)
                         run_perform = False
-                    elif config.compute_test_value == 'err':
+                    elif config.compute_test_value == 'raise':
                         raise ValueError('Cannot compute test value: input %i (%s) of Op %s missing default value' % (i, ins, node))
-                    else:
+                    elif config.compute_test_value == 'ignore':
                         # silently skip test
                         run_perform = False
+                    else:
+                        raise ValueError('%s is invalid for option config.compute_Test_value' % config.compute_test_value)
 
             # if all inputs have test-values, run the actual op
             if run_perform:
@@ -371,10 +373,8 @@ class PureOp(object):
                     # for a certain Op.
                     #TODO: use the c_thunk?
                     if config.compute_test_value == 'warn':
-                        # TODO: use warnings.warn
-                        print >>sys.stderr, 'Warning, in compute_test_value:', type(e)
-                        print >>sys.stderr, e
-                    elif config.compute_test_value == 'err':
+                        warnings.warn('Warning, in compute_test_value:' + type(e), stacklevel=2)
+                    elif config.compute_test_value == 'raise':
                         raise
 
         if self.default_output is not None:

theano/gof/tests/test_compute_test_value.py

@@ -2,9 +2,11 @@ import numpy
 import unittest
 
 import theano
+import warnings
 from theano import config
 from theano import tensor as T
 from theano.tensor.basic import _allclose
+from theano.scan_module import scan
 
 
 class TestComputeTestValue(unittest.TestCase):
@@ -12,7 +14,7 @@ class TestComputeTestValue(unittest.TestCase):
     def test_variable_only(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = T.matrix('x')
             x.tag.test_value = numpy.random.rand(3,4).astype(config.floatX)
@@ -41,22 +43,25 @@ class TestComputeTestValue(unittest.TestCase):
             y.tag.test_value = numpy.random.rand(4,5).astype(config.floatX)
 
             # should skip computation of test value
-            theano.config.compute_test_value = 'False'
+            theano.config.compute_test_value = 'off'
             z = T.dot(x,y)
             assert not hasattr(z.tag, 'test_value')
 
-            # should fail one or another when flag is set
-            theano.config.compute_test_value = 'warn'
-            self.assertRaises(Warning, T.dot, x, y)
-            theano.config.compute_test_value = 'err'
+            # should fail when asked by user
+            theano.config.compute_test_value = 'raise'
             self.assertRaises(ValueError, T.dot, x, y)
+
+            # test that a warning is raised if required
+            theano.config.compute_test_value = 'warn'
+            warnings.simplefilter('error', UserWarning)
+            self.assertRaises(UserWarning, T.dot, x, y)
         finally:
             theano.config.compute_test_value = orig_compute_test_value
 
     def test_string_var(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = T.matrix('x')
             x.tag.test_value = numpy.random.rand(3,4).astype(config.floatX)
@@ -85,7 +90,7 @@ class TestComputeTestValue(unittest.TestCase):
     def test_shared(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = T.matrix('x')
             x.tag.test_value = numpy.random.rand(3,4).astype(config.floatX)
@@ -106,7 +111,7 @@ class TestComputeTestValue(unittest.TestCase):
     def test_ndarray(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = numpy.random.rand(2,3).astype(config.floatX)
             y = theano.shared(numpy.random.rand(3,6).astype(config.floatX), 'y')
@@ -126,7 +131,7 @@ class TestComputeTestValue(unittest.TestCase):
     def test_constant(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = T.constant(numpy.random.rand(2,3), dtype=config.floatX)
             y = theano.shared(numpy.random.rand(3,6).astype(config.floatX), 'y')
@@ -146,7 +151,7 @@ class TestComputeTestValue(unittest.TestCase):
     def test_incorrect_type(self):
         orig_compute_test_value = theano.config.compute_test_value
         try:
-            theano.config.compute_test_value = 'True'
+            theano.config.compute_test_value = 'raise'
 
             x = T.fmatrix('x')
             # Incorrect dtype (float64) for test_value
@@ -157,3 +162,32 @@ class TestComputeTestValue(unittest.TestCase):
             self.assertRaises(TypeError, T.dot, x, y)
         finally:
             theano.config.compute_test_value = orig_compute_test_value
+
+    def notest_scan(self):
+        """
+        Do not run this test as the compute_test_value mechanism is known not to work with Scan.
+        TODO: fix scan to work with compute_test_value
+        """
+        orig_compute_test_value = theano.config.compute_test_value
+        try:
+            theano.config.compute_test_value = 'raise'
+            k = T.iscalar("k")
+            A = T.vector("A")
+            k.tag.test_value = 3
+            A.tag.test_value = numpy.random.rand(5)
+
+            def fx(prior_result, A):
+                return prior_results * A
+            # Symbolic description of the result
+            result, updates = theano.scan(fn=lambda prior_result, A: prior_result * A,
+                                          outputs_info=T.ones_like(A),
+                                          non_sequences=A,
+                                          n_steps=k)
+
+            # We only care about A**k, but scan has provided us with A**1 through A**k.
+            # Discard the values that we don't care about. Scan is smart enough to
+            # notice this and not waste memory saving them.
+            final_result = result[-1]
+            assert hasattr(final_result.tag, 'test_value')
+        finally:
+            theano.config.compute_test_value = orig_compute_test_value