lacks a type converter from python utf string or bytes to std::string

[inter1965]

diff --git libpyEM/libpyTypeConverter2.cpp libpyEM/libpyTypeConverter2.cpp
index c9c4461fa..5aa4ff983 100644
--- libpyEM/libpyTypeConverter2.cpp
+++ libpyEM/libpyTypeConverter2.cpp
@@ -112,6 +112,7 @@ BOOST_PYTHON_MODULE(libpyTypeConverter2)
EMAN::EMObject_to_python();
EMAN::Dict_to_python();
EMAN::String_to_python();

• EMAN::String_from_python();
  EMAN::Dict_from_python();

  EMAN::tuple3_to_pythonEMAN::IntPoint();
  diff --git libpyEM/typeconverter.h libpyEM/typeconverter.h
  index ace5ab315..34b474b55 100644
  --- libpyEM/typeconverter.h
  +++ libpyEM/typeconverter.h
  @@ -915,6 +916,51 @@ namespace EMAN {

  };

• struct String_from_python {

•   String_from_python() {
  

•   	boost::python::converter::registry::push_back(
  

•   		&convertible,
  

•   		&construct,
  

•   		boost::python::type_id<std::string>());
  

•   }
  

•   // Determine if obj_ptr can be converted in a std::string
  

•   static void* convertible(PyObject* obj_ptr) {
  

•   	if (!PyUnicode_Check(obj_ptr) && !PyBytes_Check(obj_ptr)) {
  

•   		return 0;
  

•   	}
  

•   	return obj_ptr;
  

•   }
  

•   // Convert obj_ptr into a std::string
  

•   static void construct(
  

•   	PyObject* obj_ptr,
  

•   	boost::python::converter::rvalue_from_python_stage1_data* data)	{
  

•   	const char* value(nullptr);
  

•   	boost::python::object temp_bytes_obj;
  

•   	if (PyUnicode_Check(obj_ptr)) {
  

•   		PyObject * temp_bytes(PyUnicode_AsEncodedString(obj_ptr, "UTF-8", "strict")); // Owned reference
  

•   		if (temp_bytes != nullptr) {
  

•   			// Take over lifetime management of temp_bytes
  

•   			temp_bytes_obj = boost::python::object(boost::python::handle<>(temp_bytes));
  

•   			value = PyBytes_AS_STRING(temp_bytes);
  

•   		} else {
  

•   			boost::python::throw_error_already_set();
  

•   		}
  

•   	} else if (PyBytes_Check(obj_ptr)) {
  

•   		value = PyBytes_AS_STRING(obj_ptr);
  

•   	} else {
  

•   		boost::python::throw_error_already_set();
  

•   	}
  

•   	if (value == nullptr) boost::python::throw_error_already_set();
  

•   	void* storage = (
  

•   		(boost::python::converter::rvalue_from_python_storage<std::string>*)
  

•   		data)->storage.bytes;
  

•   	new (storage) std::string(value);
  

•   	data->convertible = storage;		
  

• 	}
  

• };

}