Merge pull request #3605 from fvisin/tag.test_value

doc/library/config.txt

@@ -861,6 +861,13 @@ import theano and print the config variable, as in:
    optimization phase. Theano user's do not need to use this. This is
    to help debug shape error in Theano optimization.
 
+.. attribute:: print_test_value
+
+    Bool value, default: False 
+
+    If ``'True'``, Theano will override the '__str__' method of its variables 
+    to also print the tag.test_value when this is available.
+
 .. attribute:: reoptimize_unpickled_function
 
     Bool value, default: False (changed in master after Theano 0.7 release)

theano/configdefaults.py

@@ -644,6 +644,16 @@ AddConfigVar(
     in_c_key=False)
 
 
+AddConfigVar(
+    'print_test_value',
+    ("If 'True', the __eval__ of a Theano variable will return its test_value "
+     "when this is available. This has the practical conseguence that, e.g., "
+     "in debugging `my_var` will print the same as `my_var.tag.test_value` "
+     "when a test value is defined."),
+    BoolParam(False),
+    in_c_key=False)
+
+
 AddConfigVar('compute_test_value_opt',
              ("For debugging Theano optimization only."
               " Same as compute_test_value, but is used"

theano/gof/graph.py

@@ -12,6 +12,7 @@ from copy import copy
 from itertools import count
 
 import theano
+from theano import config
 from theano.gof import utils
 from six import string_types, integer_types, iteritems
 from theano.misc.ordered_set import OrderedSet
@@ -391,8 +392,7 @@ class Variable(Node):
         self.auto_name = 'auto_' + str(next(self.__count__))
 
     def __str__(self):
-        """
-        WRITEME
+        """Return a str representation of the Variable.
 
         """
         if self.name is not None:
@@ -406,8 +406,29 @@ class Variable(Node):
         else:
             return "<%s>" % str(self.type)
 
-    def __repr__(self):
-        return str(self)
+    def __repr_test_value__(self):
+        """Return a repr of the test value.
+
+        Return a printable representation of the test value. It can be
+        overridden by classes with non printable test_value to provide a
+        suitable representation of the test_value.
+        """
+        return repr(theano.gof.op.get_test_value(self))
+
+    def __repr__(self, firstPass=True):
+        """Return a repr of the Variable.
+
+        Return a printable name or description of the Variable. If
+        config.print_test_value is True it will also print the test_value if
+        any.
+        """
+        to_print = [str(self)]
+        if config.print_test_value and firstPass:
+            try:
+                to_print.append(self.__repr_test_value__())
+            except AttributeError:
+                pass
+        return '\n'.join(to_print)
 
     def clone(self):
         """

theano/sandbox/cuda/var.py

@@ -43,6 +43,10 @@ class _operators(tensor.basic._tensor_py_operators):
 
 class CudaNdarrayVariable(_operators, Variable):
     pass
+
+    # override default
+    def __repr_test_value__(self):
+        return repr(numpy.array(theano.gof.op.get_test_value(self)))
 CudaNdarrayType.Variable = CudaNdarrayVariable
 
 

theano/sandbox/gpuarray/type.py

@@ -420,6 +420,9 @@ class _operators(_tensor_py_operators):
 
 
 class GpuArrayVariable(_operators, Variable):
+    # override the default
+    def __repr_test_value__(self):
+        return repr(numpy.array(theano.gof.op.get_test_value(self)))
     pass