Use more frequently the pprint dict.

theano/tensor/basic.py

@@ -4113,8 +4113,7 @@ class Join(Op):
 
 join = Join()
 
-pprint.assign(lambda pstate, r: r.owner and isinstance(r.owner.op, Join),
-              printing.FunctionPrinter('join'))
+pprint.assign(Join, printing.FunctionPrinter('join'))
 
 
 def roll(x, shift, axis=None):

theano/tensor/elemwise.py

@@ -446,8 +446,7 @@ class DimShufflePrinter:
         else:
             raise TypeError("Can only print DimShuffle.")
 
-pprint.assign(lambda pstate, r: r.owner and isinstance(r.owner.op, DimShuffle),
-              DimShufflePrinter())
+pprint.assign(DimShuffle, DimShufflePrinter())
 
 
 ################

theano/tensor/inplace.py

@@ -26,12 +26,7 @@ def _scal_inplace(symbol):
     rval.__epydoc_asRoutine = symbol
     rval.__module__ = 'theano.tensor.inplace'
 
-    def chk(pstate, r):
-        if not r.owner:
-            return False
-        return r.owner.op == rval
-
-    pprint.assign(chk, printing.FunctionPrinter(symbolname.replace('_inplace', '=')))
+    pprint.assign(rval, printing.FunctionPrinter(symbolname.replace('_inplace', '=')))
     return rval
 
 

theano/tensor/opt.py

@@ -869,8 +869,7 @@ class MakeVectorPrinter:
         else:
             raise TypeError("Can only print make_vector.")
 
-T.pprint.assign(lambda pstate, r: r.owner and
-                isinstance(r.owner.op, MakeVector), MakeVectorPrinter())
+T.pprint.assign(MakeVector, MakeVectorPrinter())
 
 
 class ShapeFeature(object):

theano/tensor/subtensor.py

@@ -1002,8 +1002,7 @@ class SubtensorPrinter:
         else:
             raise TypeError("Can only print Subtensor.")
 
-pprint.assign(lambda pstate, r: r.owner and isinstance(r.owner.op, Subtensor),
-              SubtensorPrinter())
+pprint.assign(Subtensor, SubtensorPrinter())
 
 
 def set_subtensor(x, y, inplace=False,