Same implementation for __repr__ and __str__

1. Write the exposed method:

   @ExposedMethod(names = {"__str__", "__repr__"})
   final PyString foo_toString() {
       // Implementation
   }

2. Override toString() and manually call exposed method:

   @Override
   public String toString() {
       return foo__repr__().toString()
   }

[The second step is to keep the builtins repr() and str() working. repr() calls PyObject#__repr__(), which calls Object#toString(). And str() calls PyObject#__str__() which calls PyObject#__repr__()]

Different implementations for __str__ and __repr__

1. Write the exposed __str__ and call it from the overriden __str__:

   @ExposedMethod
   final PyString foo___str__() {
       // Implementation
   }
   
   @Override
   public PyString __str__() {
       return foo__str__();
   }

2. Same thing for __repr__:

   @ExposedMethod
   final PyString foo___repr__() {
       // Implementation
   }
   
   @Override
   public PyString __repr__() {
       return foo__repr__();
   }

3. Override toString:

   @Override
   public String toString() {
       return foo___str__().toString()
   }

[Now, once you have overridden the three important methods, you don't have to care about the interrelations which are present on the default implementations of PyObject]

Only implement __str__

Follow the step 1 of the previous recipe. Optionally you can also follow the step 3 if you want to map toString() to __str__() .