add function to give variables unique names

theano/gof/tests/test_utils.py

+import theano
+from theano.gof.utils import give_variables_names, unique
+
+def test_variables_with_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])

theano/gof/utils.py

@@ -7,7 +7,7 @@ import re, os, traceback
 
 def add_tag_trace(thing):
     """Add tag.trace to an node or variable.
-    
+
     The argument is returned after being affected (inplace).
     """
     limit = config.traceback.limit
@@ -20,7 +20,7 @@ def hashgen():
     return  hashgen.next
 hashgen.next = 0
 
-class MethodNotDefined(Exception): 
+class MethodNotDefined(Exception):
     """
     To be raised by functions defined as part of an interface.
 
@@ -78,7 +78,7 @@ def memoize(f):
 
 def deprecated(filename, msg=''):
     """Decorator which will print a warning message on the first call.
-    
+
     Use it like this:
 
     @deprecated('myfile', 'do something different...')
@@ -107,9 +107,9 @@ def uniq(seq):
 
 def difference(seq1, seq2):
     """
-    Returns all elements in seq1 which are not in seq2: i.e seq1\seq2 
+    Returns all elements in seq1 which are not in seq2: i.e seq1\seq2
     """
-    try: 
+    try:
         # try to use O(const * len(seq1)) algo
         if len(seq2) < 4: # I'm guessing this threshold -JB
             raise Exception('not worth it')
@@ -131,7 +131,7 @@ def partition(f, seq):
         else:
             seqf.append(elem)
     return seqt, seqf
-    
+
 def attr_checker(*attrs):
     def f(candidate):
         for attr in attrs:
@@ -204,7 +204,7 @@ def toposort(prereqs_d):
 #     for x, y in prereqs_d.items():
 #         all2.update(y)
 #     print all1.difference(all2)
-    
+
     seq = []
     done = set()
     postreqs_d = {}
@@ -330,3 +330,27 @@ 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."""
+    names = map(lambda var: var.name, variables)
+    h = hist(names)
+    bad_var = lambda var: 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