+ example of sequence protocol of Python type

src/Mod/Sandbox/App/AppSandbox.cpp

@@ -52,6 +52,9 @@ public:
             Py::String name( names[i] );
             std::cout << "    " << name << std::endl;
         }
+        m_array.push_back(Py::Long(2));
+        m_array.push_back(Py::Float(3.0));
+        m_array.push_back(Py::String("4.0"));
     }
 
     virtual ~PythonBaseClass()
@@ -65,6 +68,7 @@ public:
         behaviors().doc( "documentation for PythonBaseClass class" );
         behaviors().supportGetattro();
         behaviors().supportSetattro();
+        behaviors().supportSequenceType();
 
         PYCXX_ADD_NOARGS_METHOD( func_noargs, PythonBaseClass_func_noargs, "docs for PythonBaseClass_func_noargs" );
         PYCXX_ADD_VARARGS_METHOD( func_varargs, PythonBaseClass_func_varargs, "docs for PythonBaseClass_func_varargs" );
@@ -142,8 +146,49 @@ public:
             return genericSetAttro( name_, value );
         }
     }
+    virtual int sequence_length()
+    {
+        // len(x)
+        return m_array.size();
+    }
+    virtual Py::Object sequence_concat(const Py::Object & i)
+    {
+        // x + y
+        throw Py::NotImplementedError("not yet implemented");
+    }
+    virtual Py::Object sequence_repeat(Py_ssize_t i)
+    {
+        // x * 3
+        throw Py::NotImplementedError("not yet implemented");
+    }
+    virtual Py::Object sequence_item(Py_ssize_t i)
+    {
+        // x[0]
+        if (i >= static_cast<Py_ssize_t>(m_array.size()))
+            throw Py::IndexError("index out of range");
+        return m_array[i];
+    }
+    virtual Py::Object sequence_slice(Py_ssize_t i, Py_ssize_t j)
+    {
+        // x[0:3]
+        throw Py::NotImplementedError("not yet implemented");
+    }
+    virtual int sequence_ass_item(Py_ssize_t i, const Py::Object & o)
+    {
+        // x[0] = y
+        if (i >= static_cast<Py_ssize_t>(m_array.size()))
+            throw Py::IndexError("index out of range");
+        m_array[i] = o;
+        return 0;
+    }
+    virtual int sequence_ass_slice(Py_ssize_t i, Py_ssize_t j, const Py::Object & o)
+    {
+        // x[0:3] = y
+        throw Py::NotImplementedError("not yet implemented");
+    }
 
     Py::String m_value;
+    std::vector<Py::Object> m_array;
 };
 
 /* module functions */