Implement __new__ for PostProcessors

Allows PostProcessors to be instansiated through python class constructor.

bindings/python/src/processors.rs

@@ -8,31 +8,31 @@ pub struct PostProcessor {
     pub processor: Container<dyn tk::tokenizer::PostProcessor + Sync>,
 }
 
-#[pyclass]
+#[pyclass(extends=PostProcessor)]
 pub struct BertProcessing {}
 #[pymethods]
 impl BertProcessing {
-    #[staticmethod]
-    fn new(sep: (String, u32), cls: (String, u32)) -> PyResult<PostProcessor> {
-        Ok(PostProcessor {
+    #[new]
+    fn new(obj: &PyRawObject, sep: (String, u32), cls: (String, u32)) -> PyResult<()> {
+        Ok(obj.init(PostProcessor {
             processor: Container::Owned(Box::new(tk::processors::bert::BertProcessing::new(
                 sep, cls,
             ))),
-        })
+        }))
     }
 }
 
 
-#[pyclass]
+#[pyclass(extends=PostProcessor)]
 pub struct RobertaProcessing {}
 #[pymethods]
 impl RobertaProcessing {
-    #[staticmethod]
-    fn new(sep: (String, u32), cls: (String, u32)) -> PyResult<PostProcessor> {
-        Ok(PostProcessor {
+    #[new]
+    fn new(obj: &PyRawObject, sep: (String, u32), cls: (String, u32)) -> PyResult<()> {
+        Ok(obj.init(PostProcessor {
             processor: Container::Owned(Box::new(tk::processors::roberta::RobertaProcessing::new(
                 sep, cls,
             ))),
-        })
+        }))
     }
-}
+}