|  | ATLAS Offline Software
    | 
 
 
 
#include <xAODtoHepMCTool.h>
|  | 
|  | xAODtoHepMCTool (const std::string &name) | 
|  | 
| virtual | ~xAODtoHepMCTool () | 
|  | 
| virtual StatusCode | initialize () override | 
|  | Dummy implementation of the initialisation function.  More... 
 | 
|  | 
| StatusCode | finalize () override | 
|  | 
| std::vector< HepMC::GenEvent > | getHepMCEvents (const xAOD::TruthEventContainer *xTruthEventContainer, const xAOD::EventInfo *eventInfo) const override | 
|  | 
| virtual void | print () const | 
|  | Print the state of the tool.  More... 
 | 
|  | 
| ServiceHandle< StoreGateSvc > & | evtStore () | 
|  | The standard StoreGateSvc(event store) Returns (kind of) a pointer to theStoreGateSvc.  More...
 | 
|  | 
| const ServiceHandle< StoreGateSvc > & | evtStore () const | 
|  | The standard StoreGateSvc(event store) Returns (kind of) a pointer to theStoreGateSvc.  More...
 | 
|  | 
| const ServiceHandle< StoreGateSvc > & | detStore () const | 
|  | The standard StoreGateSvc/DetectorStoreReturns (kind of) a pointer to theStoreGateSvc.  More...
 | 
|  | 
| virtual StatusCode | sysInitialize () override | 
|  | Perform system initialization for an algorithm.  More... 
 | 
|  | 
| virtual StatusCode | sysStart () override | 
|  | Handle START transition.  More... 
 | 
|  | 
| virtual std::vector< Gaudi::DataHandle * > | inputHandles () const override | 
|  | Return this algorithm's input handles.  More... 
 | 
|  | 
| virtual std::vector< Gaudi::DataHandle * > | outputHandles () const override | 
|  | Return this algorithm's output handles.  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase & | declareProperty (Gaudi::Property< T, V, H > &t) | 
|  | 
| Gaudi::Details::PropertyBase * | declareProperty (const std::string &name, SG::VarHandleKey &hndl, const std::string &doc, const SG::VarHandleKeyType &) | 
|  | Declare a new Gaudi property.  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase * | declareProperty (const std::string &name, SG::VarHandleBase &hndl, const std::string &doc, const SG::VarHandleType &) | 
|  | Declare a new Gaudi property.  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase * | declareProperty (const std::string &name, SG::VarHandleKeyArray &hndArr, const std::string &doc, const SG::VarHandleKeyArrayType &) | 
|  | 
| Gaudi::Details::PropertyBase * | declareProperty (const std::string &name, T &property, const std::string &doc, const SG::NotHandleType &) | 
|  | Declare a new Gaudi property.  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase * | declareProperty (const std::string &name, T &property, const std::string &doc="none") | 
|  | Declare a new Gaudi property.  More... 
 | 
|  | 
| void | updateVHKA (Gaudi::Details::PropertyBase &) | 
|  | 
| MsgStream & | msg () const | 
|  | 
| MsgStream & | msg (const MSG::Level lvl) const | 
|  | 
| bool | msgLvl (const MSG::Level lvl) const | 
|  | 
|  | 
| HepMC::GenEvent | createHepMCEvent (const xAOD::TruthEvent *xEvt, const xAOD::EventInfo *eventInfo) const | 
|  | 
| HepMC::GenVertexPtr | vertexHelper (const xAOD::TruthVertex *, std::map< const xAOD::TruthVertex *, HepMC::GenVertexPtr > &, bool &) const | 
|  | 
| HepMC::GenParticlePtr | createHepMCParticle (const xAOD::TruthParticle *) const | 
|  | 
| HepMC::GenVertexPtr | createHepMCVertex (const xAOD::TruthVertex *) const | 
|  | 
| void | printxAODEvent (const xAOD::TruthEvent *event, const xAOD::EventInfo *eventInfo) const | 
|  | 
| Gaudi::Details::PropertyBase & | declareGaudiProperty (Gaudi::Property< T, V, H > &hndl, const SG::VarHandleKeyType &) | 
|  | specialization for handling Gaudi::Property<SG::VarHandleKey>  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase & | declareGaudiProperty (Gaudi::Property< T, V, H > &hndl, const SG::VarHandleKeyArrayType &) | 
|  | specialization for handling Gaudi::Property<SG::VarHandleKeyArray>  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase & | declareGaudiProperty (Gaudi::Property< T, V, H > &hndl, const SG::VarHandleType &) | 
|  | specialization for handling Gaudi::Property<SG::VarHandleBase>  More... 
 | 
|  | 
| Gaudi::Details::PropertyBase & | declareGaudiProperty (Gaudi::Property< T, V, H > &t, const SG::NotHandleType &) | 
|  | specialization for handling everything that's not a Gaudi::Property<SG::VarHandleKey> or a <SG::VarHandleKeyArray>  More... 
 | 
|  | 
Definition at line 22 of file xAODtoHepMCTool.h.
 
◆ StoreGateSvc_t
◆ xAODtoHepMCTool()
      
        
          | xAODtoHepMCTool::xAODtoHepMCTool | ( | const std::string & | name | ) |  | 
      
 
 
◆ ~xAODtoHepMCTool()
  
  | 
        
          | virtual xAODtoHepMCTool::~xAODtoHepMCTool | ( |  | ) |  |  | inlinevirtual | 
 
 
◆ createHepMCEvent()
EVENT LEVEL
Avoid double deletion
Definition at line 90 of file xAODtoHepMCTool.cxx.
   94   HepMC::GenEvent genEvt;
 
  100   genEvt.set_event_number(evtNum);
 
  101   ATH_MSG_DEBUG(
"Start createHepMCEvent for event " << evtNum);
 
  104   #ifndef XAOD_STANDALONE 
  106   std::map<std::string, int> weightNameMap;
 
  111   std::shared_ptr<HepMC3::GenRunInfo> 
runinfo = std::make_shared<HepMC3::GenRunInfo>();
 
  112   genEvt.set_run_info(std::move(
runinfo));
 
  113   std::vector<std::string> wnames;
 
  114   wnames.reserve(
weights.size());
 
  116     for (
const auto& 
it : weightNameMap) {
 
  117       if (
it.second == 
idx) {
 
  118         wnames.push_back(
it.first);
 
  123   genEvt.run_info()->set_weight_names(wnames);
 
  124   for ( std::vector<float>::const_iterator wgt = 
weights.begin(); wgt != 
weights.end(); ++wgt ) {
 
  125     genEvt.weights().push_back(*wgt);
 
  128   if (weightNameMap.size()) {
 
  129     HepMC::WeightContainer& wc = genEvt.weights();
 
  132       for (
const auto& 
it : weightNameMap) {
 
  133         if (
it.second == 
idx) {
 
  141     for ( std::vector<float>::const_iterator wgt = 
weights.begin(); wgt != 
weights.end(); ++wgt ) {
 
  142       genEvt.weights().push_back(*wgt);
 
  150   std::map<const xAOD::TruthVertex *, HepMC::GenVertexPtr> vertexMap;
 
  154     if (!tlink.isValid()) { 
continue; }
 
  158     if (xPart == 
nullptr) {
 
  159       ATH_MSG_WARNING(
"xAOD TruthParticle is equal to NULL. This should not happen!");
 
  184       bool prodVtxSeenBefore(
false); 
 
  185       auto hepmcProdVtx = 
vertexHelper(xAODProdVtx, vertexMap, prodVtxSeenBefore);
 
  188       hepmcProdVtx->add_particle_out(hepmcParticle);
 
  190       hepmcProdVtx->add_particle_out(hepmcParticle.get());
 
  193       if (!prodVtxSeenBefore) {
 
  194         genEvt.add_vertex(std::move(hepmcProdVtx));
 
  207         if (xPart->
hasProdVtx()) { (void)hepmcParticle.release(); }
 
  211       bool decayVtxSeenBefore(
false); 
 
  212       auto hepmcDecayVtx = 
vertexHelper(xAODDecayVtx, vertexMap, decayVtxSeenBefore);
 
  215       hepmcDecayVtx->add_particle_in(std::move(hepmcParticle));
 
  217       hepmcDecayVtx->add_particle_in(hepmcParticle.get());
 
  220       if (!decayVtxSeenBefore) {
 
  221         genEvt.add_vertex(std::move(hepmcDecayVtx));
 
  225     (void)hepmcParticle.release();
 
 
 
 
◆ createHepMCParticle()
◆ createHepMCVertex()
◆ declareGaudiProperty() [1/4]
specialization for handling Gaudi::Property<SG::VarHandleKeyArray> 
Definition at line 170 of file AthCommonDataStore.h.
  175                                                        hndl.documentation());
 
 
 
 
◆ declareGaudiProperty() [2/4]
specialization for handling Gaudi::Property<SG::VarHandleKey> 
Definition at line 156 of file AthCommonDataStore.h.
  161                                                        hndl.documentation());
 
 
 
 
◆ declareGaudiProperty() [3/4]
specialization for handling Gaudi::Property<SG::VarHandleBase> 
Definition at line 184 of file AthCommonDataStore.h.
  189                                                        hndl.documentation());
 
 
 
 
◆ declareGaudiProperty() [4/4]
◆ declareProperty() [1/6]
Declare a new Gaudi property. 
- Parameters
- 
  
    | name | Name of the property. |  | hndl | Object holding the property value. |  | doc | Documentation string for the property. |  
 
This is the version for types that derive from SG::VarHandleBase. The property value object is put on the input and output lists as appropriate; then we forward to the base class. 
Definition at line 245 of file AthCommonDataStore.h.
  250     this->declare(hndl.
vhKey());
 
  251     hndl.
vhKey().setOwner(
this);
 
  253     return PBASE::declareProperty(
name,hndl,
doc);
 
 
 
 
◆ declareProperty() [2/6]
Declare a new Gaudi property. 
- Parameters
- 
  
    | name | Name of the property. |  | hndl | Object holding the property value. |  | doc | Documentation string for the property. |  
 
This is the version for types that derive from SG::VarHandleKey. The property value object is put on the input and output lists as appropriate; then we forward to the base class. 
Definition at line 221 of file AthCommonDataStore.h.
  229     return PBASE::declareProperty(
name,hndl,
doc);
 
 
 
 
◆ declareProperty() [3/6]
◆ declareProperty() [4/6]
Declare a new Gaudi property. 
- Parameters
- 
  
    | name | Name of the property. |  | property | Object holding the property value. |  | doc | Documentation string for the property. |  
 
This is the generic version, for types that do not derive from SG::VarHandleKey. It just forwards to the base class version of declareProperty. 
Definition at line 333 of file AthCommonDataStore.h.
  338     return PBASE::declareProperty(
name, property, 
doc);
 
 
 
 
◆ declareProperty() [5/6]
Declare a new Gaudi property. 
- Parameters
- 
  
    | name | Name of the property. |  | property | Object holding the property value. |  | doc | Documentation string for the property. |  
 
This dispatches to either the generic declareProperty or the one for VarHandle/Key/KeyArray. 
Definition at line 352 of file AthCommonDataStore.h.
 
 
◆ declareProperty() [6/6]
◆ detStore()
◆ evtStore() [1/2]
◆ evtStore() [2/2]
◆ extraDeps_update_handler()
Add StoreName to extra input/output deps as needed. 
use the logic of the VarHandleKey to parse the DataObjID keys supplied via the ExtraInputs and ExtraOuputs Properties to add the StoreName if it's not explicitly given 
 
 
◆ finalize()
  
  | 
        
          | StatusCode xAODtoHepMCTool::finalize | ( |  | ) |  |  | overridevirtual | 
 
Implements IxAODtoHepMCTool.
Definition at line 23 of file xAODtoHepMCTool.cxx.
   25   ATH_MSG_INFO(
"==============================================================");
 
   26   ATH_MSG_INFO(
"==========    xAOD -> HepMC Tool :: Run Summary     ==========");
 
   27   ATH_MSG_INFO(
"==============================================================");
 
   39     ATH_MSG_INFO(
"Inconsistencies with the beam particles storage in the event record!");
 
   46   ATH_MSG_INFO(
"==============================================================");
 
   47   ATH_MSG_INFO(
"===================    End Run Summary     ===================");
 
   48   ATH_MSG_INFO(
"==============================================================");
 
   49   return StatusCode::SUCCESS;
 
 
 
 
◆ getHepMCEvents()
Implements IxAODtoHepMCTool.
Definition at line 52 of file xAODtoHepMCTool.cxx.
   57   std::vector<HepMC::GenEvent> mcEventCollection;
 
   71     std::shared_ptr<HepMC3::GenRunInfo> 
runinfo = std::make_shared<HepMC3::GenRunInfo>(*(hepmcEvent.run_info().get()));
 
   79     mcEventCollection.push_back(std::move(hepmcEvent));
 
   81     mcEventCollection[mcEventCollection.size()-1].set_run_info(std::move(
runinfo));
 
   87   return mcEventCollection;
 
 
 
 
◆ getKey()
Get the (hashed) key of an object that is in the event store. 
This is a bit of a special one. StoreGateSvc and xAOD::TEvent both provide ways for getting the SG::sgkey_t key for an object that is in the store, based on a bare pointer. But they provide different interfaces for doing so.
In order to allow tools to efficiently perform this operation, they can use this helper function.
- See also
- asg::AsgTool::getName
- Parameters
- 
  
    | ptr | The bare pointer to the object that the event store should know about |  
 
- Returns
- The hashed key of the object in the store. If not found, an invalid (zero) key. 
Definition at line 119 of file AsgTool.cxx.
  121 #ifdef XAOD_STANDALONE 
  127       return ( 
proxy == 
nullptr ? 0 : 
proxy->sgkey() );
 
  128 #endif // XAOD_STANDALONE 
 
 
 
◆ getName()
  
  | 
        
          | const std::string & asg::AsgTool::getName | ( | const void * | ptr | ) | const |  | inherited | 
 
Get the name of an object that is / should be in the event store. 
This is a bit of a special one. StoreGateSvc and xAOD::TEvent both provide ways for getting the std::string name for an object that is in the store, based on a bare pointer. But they provide different interfaces for doing so.
In order to allow tools to efficiently perform this operation, they can use this helper function.
- See also
- asg::AsgTool::getKey
- Parameters
- 
  
    | ptr | The bare pointer to the object that the event store should know about |  
 
- Returns
- The string name of the object in the store. If not found, an empty string. 
Definition at line 106 of file AsgTool.cxx.
  108 #ifdef XAOD_STANDALONE 
  114       static const std::string 
dummy = 
"";
 
  116 #endif // XAOD_STANDALONE 
 
 
 
◆ getProperty()
template<class T > 
  
  | 
        
          | const T* asg::AsgTool::getProperty | ( | const std::string & | name | ) | const |  | inherited | 
 
Get one of the tool's properties. 
 
 
◆ initialize()
  
  | 
        
          | StatusCode xAODtoHepMCTool::initialize | ( |  | ) |  |  | overridevirtual | 
 
Dummy implementation of the initialisation function. 
It's here to allow the dual-use tools to skip defining an initialisation function. Since many are doing so... 
Reimplemented from asg::AsgTool.
Definition at line 16 of file xAODtoHepMCTool.cxx.
   20   return StatusCode::SUCCESS;
 
 
 
 
◆ inputHandles()
Return this algorithm's input handles. 
We override this to include handle instances from key arrays if they have not yet been declared. See comments on updateVHKA. 
 
 
◆ msg() [1/2]
◆ msg() [2/2]
◆ msg_level_name()
  
  | 
        
          | const std::string & asg::AsgTool::msg_level_name | ( |  | ) | const |  | inherited | 
 
A deprecated function for getting the message level's name. 
Instead of using this, weirdly named function, user code should get the string name of the current minimum message level (in case they really need it...), with:
 MSG::name( msg().level() ) 
This function's name doesn't follow the ATLAS coding rules, and as such will be removed in the not too distant future.
- Returns
- The string name of the current minimum message level that's printed 
Definition at line 101 of file AsgTool.cxx.
 
 
◆ msgLvl()
◆ outputHandles()
Return this algorithm's output handles. 
We override this to include handle instances from key arrays if they have not yet been declared. See comments on updateVHKA. 
 
 
◆ print()
  
  | 
        
          | void asg::AsgTool::print | ( |  | ) | const |  | virtualinherited | 
 
Print the state of the tool. 
Implements asg::IAsgTool.
Reimplemented in JetRecTool, JetFinder, JetModifiedMassDrop, JetFromPseudojet, JetReclusterer, JetReclusteringTool, JetTruthLabelingTool, JetPileupLabelingTool, HI::HIPileupTool, LundVariablesTool, JetDumper, JetBottomUpSoftDrop, JetRecursiveSoftDrop, JetSoftDrop, JetConstituentsRetriever, JetSubStructureMomentToolsBase, JetSplitter, JetToolRunner, JetPruner, JetPseudojetRetriever, JetTrimmer, AsgHelloTool, and KtDeltaRTool.
Definition at line 131 of file AsgTool.cxx.
 
 
◆ printxAODEvent()
Definition at line 279 of file xAODtoHepMCTool.cxx.
  282   std::vector<int> uidPars;
 
  283   std::vector<int> uidKids;
 
  287   std::cout << 
"======================================================================================" << std::endl;
 
  288   std::cout << 
"xAODTruth Event " << evtNum << std::endl;
 
  289   std::cout << 
"   UniqueID      PDG Id  Status   px(GeV)   py(GeV)   pz(GeV)    E(GeV)   Parent: Decay" << std::endl;
 
  290   std::cout << 
"   -----------------------------------------------------------------------------------" << std::endl;
 
  292   int nPart = 
event->nTruthParticles();
 
  293   std::ios oldState(
nullptr); 
 
  294   oldState.copyfmt(std::cout); 
 
  295   for (
int i = 0; 
i < nPart; ++
i)
 
  298     if (
part == 
nullptr) 
continue;
 
  300     int id = 
part->pdgId();
 
  301     if (
id != 25) 
continue;
 
  303     float px = 
part->px() / 1000.;
 
  304     float py = 
part->py() / 1000.;
 
  305     float pz = 
part->pz() / 1000.;
 
  306     float e = 
part->e() / 1000.;
 
  310     if (
part->hasProdVtx())
 
  317     if (
part->hasDecayVtx())
 
  326               << std::setw(8) << 
stat 
  327               << std::setprecision(2) << std::fixed
 
  328               << std::setw(10) << 
px << std::setw(10) << 
py 
  329               << std::setw(10) << 
pz << std::setw(10) << 
e << 
"   ";
 
  331     for (
unsigned int k = 0; 
k < uidPars.size(); ++
k)
 
  333       std::cout << uidPars[
k] << 
" ";
 
  336     for (
unsigned int k = 0; 
k < uidKids.size(); ++
k)
 
  338       std::cout << uidKids[
k] << 
" ";
 
  340     std::cout << std::endl;
 
  342   std::cout << 
"======================================================================================" << std::endl;
 
  343   std::cout.copyfmt(oldState);
 
 
 
 
◆ renounce()
◆ renounceArray()
◆ sysInitialize()
◆ sysStart()
Handle START transition. 
We override this in order to make sure that conditions handle keys can cache a pointer to the conditions container. 
 
 
◆ updateVHKA()
◆ vertexHelper()
Definition at line 235 of file xAODtoHepMCTool.cxx.
  242   vMapItr = vertexMap.find(xaodVertex);
 
  244   if (vMapItr != vertexMap.end()) {
 
  246     hepmcVertex = (*vMapItr).second;
 
  252     hepmcVertex = vertexMap[xaodVertex];
 
 
 
 
◆ m_badBeams
  
  | 
        
          | int xAODtoHepMCTool::m_badBeams {} |  | private | 
 
 
◆ m_badSuggest
  
  | 
        
          | std::atomic<int> xAODtoHepMCTool::m_badSuggest {} |  | mutableprivate | 
 
 
◆ m_detStore
◆ m_evtCount
  
  | 
        
          | std::atomic<int> xAODtoHepMCTool::m_evtCount {} |  | mutableprivate | 
 
 
◆ m_evtStore
◆ m_lenFac
  
  | 
        
          | Gaudi::Property<float> xAODtoHepMCTool::m_lenFac |  | private | 
 
Initial value:{
            this, "LengthFactor", 1.0,
            "Scale factor to be applied to truth lengths to convert from mm, e.g. 0.01 to go to cm"}
Definition at line 46 of file xAODtoHepMCTool.h.
 
 
◆ m_maxCount
  
  | 
        
          | Gaudi::Property<int> xAODtoHepMCTool::m_maxCount |  | private | 
 
Initial value:{
            this, "PrintNevents", 0,
            "Maximum number of events to print out"}
Definition at line 52 of file xAODtoHepMCTool.h.
 
 
◆ m_momFac
  
  | 
        
          | Gaudi::Property<float> xAODtoHepMCTool::m_momFac |  | private | 
 
Initial value:{
            this, "MomentFactor", 0.001,
            "Scale factor to be applied to truth energy and momenta to convert from MeV, e.g. 0.001 to go to GeV"}
Input container key (job property) 
Definition at line 43 of file xAODtoHepMCTool.h.
 
 
◆ m_noProdVtx
  
  | 
        
          | int xAODtoHepMCTool::m_noProdVtx {} |  | private | 
 
 
◆ m_signalOnly
  
  | 
        
          | Gaudi::Property<bool> xAODtoHepMCTool::m_signalOnly |  | private | 
 
Initial value:{
            this, "SignalOnly", true,
            "Convert only the signal event (true), or all events found"}
Definition at line 49 of file xAODtoHepMCTool.h.
 
 
◆ m_varHandleArraysDeclared
◆ m_vhka
The documentation for this class was generated from the following files:
 
HepMC::GenVertex * GenVertexPtr
JetConstituentVector::iterator iterator
constexpr ParticleHypothesis particle[PARTICLEHYPOTHESES]
the array of masses
uint64_t eventNumber() const
The current event's event number.
StoreGateSvc_t m_evtStore
Pointer to StoreGate (event store by default)
std::vector< SG::VarHandleKeyArray * > m_vhka
#define ATH_MSG_VERBOSE(x)
void line(std::ostream &os, const GenEvent &e)
virtual void setOwner(IDataHandleHolder *o)=0
Gaudi::Details::PropertyBase & declareGaudiProperty(Gaudi::Property< T, V, H > &hndl, const SG::VarHandleKeyType &)
specialization for handling Gaudi::Property<SG::VarHandleKey>
ServiceHandle< StoreGateSvc > & evtStore()
The standard StoreGateSvc (event store) Returns (kind of) a pointer to the StoreGateSvc.
bool hasDecayVtx() const
Check for a decay vertex on this particle.
bool is_simulation_particle(const T &p)
Method to establish if a particle (or barcode) was created during the simulation (TODO update to be s...
GenVertexPtr newGenVertexPtr(const HepMC::FourVector &pos=HepMC::FourVector(0.0, 0.0, 0.0, 0.0), const int i=0)
Gaudi::Details::PropertyBase & declareProperty(Gaudi::Property< T, V, H > &t)
Class describing a truth particle in the MC record.
bool hasProdVtx() const
Check for a production vertex on this particle.
Class describing a signal truth event in the MC record.
const std::string & name(Level lvl)
Convenience function for translating message levels to strings.
bool is_simulation_vertex(const T &v)
Method to establish if the vertex was created during simulation (TODO migrate to be based on status).
StoreGateSvc_t m_detStore
Pointer to StoreGate (detector store by default)
virtual void renounce()=0
std::conditional< std::is_base_of< SG::VarHandleKeyArray, T >::value, VarHandleKeyArrayType, type2 >::type type
const TruthVertex_v1 * decayVtx() const
The decay vertex of this particle.
const std::vector< float > & weights() const
Const access to the weights vector.
const TruthVertex_v1 * prodVtx() const
The production vertex of this particle.
Class describing a truth vertex in the MC record.
GenParticlePtr newGenParticlePtr(const HepMC::FourVector &mom=HepMC::FourVector(0.0, 0.0, 0.0, 0.0), int pid=0, int status=0)
#define ATH_MSG_WARNING(x)
SG::VarHandleKey & vhKey()
Return a non-const reference to the HandleKey.
const TruthParticleLinks_t & truthParticleLinks() const
Get all the truth particles.
int generations(const T &p)
Method to return how many interactions a particle has undergone during simulation (TODO migrate to be...
static std::string retrieveMetadata(const std::string &folder, const std::string &key, const ServiceHandle< StoreGateSvc > &inputMetaStore)
method that always returns as a string you can use from, e.g, pyROOT with evt = ROOT....