add a parameter to thaeno flags to don't allow changing them after theano import.

theano/configparser.py

@@ -163,9 +163,14 @@ def AddConfigVar(name, doc, configparam, root=config):
         _config_var_list.append(configparam)
 
 class ConfigParam(object):
-    def __init__(self, default, filter=None):
+    def __init__(self, default, filter=None,  allow_override=True):
+        "
+        If allow_override is False, we can't change the value after the import of Theano.
+        So the value should be the same during all the execution
+        "
         self.default = default
         self.filter=filter
+        self.allow_override = allow_override
         # N.B. --
         # self.fullname  # set by AddConfigVar
         # self.doc       # set by AddConfigVar
@@ -182,6 +187,8 @@ class ConfigParam(object):
         return self.val
 
     def __set__(self, cls, val):
+        if not self.allow_override and hasattr(self,'val'):
+            raise Exception("Can't change the value of this config parameter after initialization!")
         #print "SETTING PARAM", self.fullname,(cls), val
         if self.filter:
             self.val = self.filter(val)
@@ -191,7 +198,7 @@ class ConfigParam(object):
     deleter=None
 
 class EnumStr(ConfigParam):
-    def __init__(self, default, *options):
+    def __init__(self, default, *options, **kwargs):
         self.default = default
         self.all = (default,) + options
         def filter(val):
@@ -200,13 +207,14 @@ class EnumStr(ConfigParam):
             else:
                 raise ValueError('Invalid value (%s) for configuration variable "%s". Legal options are %s'
                         % (val, self.fullname, self.all), val)
-        super(EnumStr, self).__init__(default, filter)
+        over = kwargs.get("allow_override", True)
+        super(EnumStr, self).__init__(default, filter, over)
 
     def __str__(self):
         return '%s (%s) ' % (self.fullname, self.all)
 
 class TypedParam(ConfigParam):
-    def __init__(self, default, mytype, is_valid=None):
+    def __init__(self, default, mytype, is_valid=None, allow_override=True):
         self.mytype = mytype
         def filter(val):
             casted_val = mytype(val)
@@ -217,17 +225,17 @@ class TypedParam(ConfigParam):
                     raise ValueError('Invalid value (%s) for configuration variable "%s".'
                             % (val, self.fullname), val)
             return casted_val
-        super(TypedParam, self).__init__(default, filter)
+        super(TypedParam, self).__init__(default, filter,  allow_override=allow_override)
     def __str__(self):
         return '%s (%s) ' % (self.fullname, self.mytype)
 
-def StrParam(default, is_valid=None):
-    return TypedParam(default, str, is_valid)
-def IntParam(default, is_valid=None):
-    return TypedParam(default, int, is_valid)
-def FloatParam(default, is_valid=None):
-    return TypedParam(default, float, is_valid)
-def BoolParam(default, is_valid=None):
+def StrParam(default, is_valid=None, allow_override=True):
+    return TypedParam(default, str, is_valid, allow_override=allow_override)
+def IntParam(default, is_valid=None, allow_override=True):
+    return TypedParam(default, int, is_valid, allow_override=allow_override)
+def FloatParam(default, is_valid=None, allow_override=True):
+    return TypedParam(default, float, is_valid, allow_override=allow_override)
+def BoolParam(default, is_valid=None, allow_override=True):
 #see comment at the beggining of this file.
     def booltype(s):
         if s in ['False','false','0', False]:
@@ -242,4 +250,4 @@ def BoolParam(default, is_valid=None):
             return False
     if is_valid is None:
         is_valid = is_valid_bool
-    return TypedParam(default, booltype, is_valid)
+    return TypedParam(default, booltype, is_valid, allow_override=allow_override)