CPAlgorithms: distinguish between MC and data when writing output branches

We allow to pass an optional list of branch mappings varsOnlyForMC to the Output block. This allows the use of a single config file for both MC and data runs, when the user requests MC-specific decorations to be written to the output (e.g. truth information like HadronConeExclTruthLabelID for jets).

PhysicsAnalysis/Algorithms/AsgAnalysisAlgorithms/python/OutputAnalysisConfig.py

@@ -12,6 +12,7 @@ class OutputAnalysisConfig (ConfigBlock):
         super (OutputAnalysisConfig, self).__init__ (configName)
         self.addOption ('postfix', '', type=str)
         self.addOption ('vars', [], type=None)
+        self.addOption ('varsOnlyForMC', [], type=None)
         self.addOption ('metVars', [], type=None)
         self.addOption ('containers', {}, type=None)
         self.addOption ('treeName', 'analysis', type=str)
@@ -24,6 +25,10 @@ class OutputAnalysisConfig (ConfigBlock):
 
     def makeAlgs (self, config) :
 
+        # merge the MC-specific branches into the main list only if we are not running on data
+        if config.dataType() is not DataType.Data:
+            self.vars += self.varsOnlyForMC
+
         if self.storeSelectionFlags:
             self.createSelectionFlagBranches(config)