only header in codeHeader

Sim/Export/ExportToPython.cpp

@@ -20,12 +20,13 @@
 
 std::string Py::Export::codeHeader(const std::string& code)
 {
-    return "import bornagain as ba\n" + Py::Fmt::printImportedSymbols(code) + "\n\n" + code;
+    return "import bornagain as ba\n" + Py::Fmt::printImportedSymbols(code) + "\n\n";
 }
 
 std::string Py::Export::sampleCode(const MultiLayer& sample)
 {
-    return Py::Export::codeHeader(SampleToPython().sampleCode(sample));
+    std::string sample_code = SampleToPython().sampleCode(sample);
+    return Py::Export::codeHeader(sample_code) + sample_code;
 }
 
 std::string Py::Export::simulationPlotCode(const ISimulation& simulation)

Sim/Export/SimulationToPython.cpp

@@ -368,7 +368,7 @@ std::string simulationCode(const ISimulation& simulation)
     ASSERT(simulation.sample());
     std::string code =
         SampleToPython().sampleCode(*simulation.sample()) + defineSimulate(simulation);
-    return Py::Export::codeHeader(code);
+    return Py::Export::codeHeader(code) + code;
 }
 
 } // namespace