Merge pull request #923 from mrocklin/give_variables_names

theano/gof/tests/test_utils.py

+import theano
+from theano.gof.utils import give_variables_names, unique
+
+def test_give_variables_names():
+    x = theano.tensor.matrix('x')
+    y = x + 1
+    z = theano.tensor.dot(x, y)
+    variables = (x, y, z)
+    give_variables_names(variables)
+    assert all(var.name for var in variables)
+    assert unique([var.name for var in variables])
+
+def test_give_variables_names_idempotence():
+    x = theano.tensor.matrix('x')
+    y = x + 1
+    z = theano.tensor.dot(x, y)
+    variables = (x, y, z)
+
+    give_variables_names(variables)
+    names = [var.name for var in variables]
+    give_variables_names(variables)
+    names2 = [var.name for var in variables]
+
+    assert names == names2
+
+def test_give_variables_names_small():
+    x = theano.tensor.matrix('x')
+    y = theano.tensor.dot(x, x)
+    fgraph = theano.FunctionGraph((x,), (y,))
+    give_variables_names(fgraph.variables)
+    assert all(var.name for var in fgraph.variables)
+    assert unique([var.name for var in fgraph.variables])
+

theano/gof/utils.py

@@ -330,3 +330,29 @@ def flatten(a):
         return l
     else:
         return [a]
+
+def unique(x):
+    return len(set(x)) == len(x)
+
+def hist(coll):
+    counts = {}
+    for elem in coll:
+        counts[elem] = counts.get(elem, 0) + 1
+    return counts
+
+def give_variables_names(variables):
+    """ Gives unique names to an iterable of variables. Modifies input.
+
+    This function is idempotent."""
+    names = map(lambda var: var.name, variables)
+    h = hist(names)
+    bad_var = lambda var: not var.name or h[var.name] > 1
+
+    for i, var in enumerate(filter(bad_var, variables)):
+        var.name = (var.name or "") + "_%d"%i
+
+    if not unique(map(str, variables)):
+        raise ValueError("Not all variables have unique names."
+                         "Maybe you've named some of the variables identically")
+
+    return variables