Using serde (serde_pyo3) to get __str__ and __repr__ easily. (#1588)

* Using serde (serde_pyo3) to get __str__ and __repr__ easily.

* Putting it within tokenizers, it needs to be too specific.

* Clippy is our friend.

* Ruff.

* Update the tests.

* Pretty sure this is wrong (#1589)

* Adding support for ellipsis.

* Fmt.

* Ruff.

* Fixing tokenizer.

---------

Co-authored-by: Eric Buehler <65165915+EricLBuehler@users.noreply.github.com>

bindings/python/src/trainers.rs

@@ -16,8 +16,8 @@ use tokenizers as tk;
 /// Trainer will return an instance of this class when instantiated.
 #[pyclass(module = "tokenizers.trainers", name = "Trainer", subclass)]
 #[derive(Clone, Deserialize, Serialize)]
+#[serde(transparent)]
 pub struct PyTrainer {
-    #[serde(flatten)]
     pub trainer: Arc<RwLock<TrainerWrapper>>,
 }
 
@@ -69,6 +69,16 @@ impl PyTrainer {
             Err(e) => Err(e),
         }
     }
+
+    fn __repr__(&self) -> PyResult<String> {
+        crate::utils::serde_pyo3::repr(self)
+            .map_err(|e| exceptions::PyException::new_err(e.to_string()))
+    }
+
+    fn __str__(&self) -> PyResult<String> {
+        crate::utils::serde_pyo3::to_string(self)
+            .map_err(|e| exceptions::PyException::new_err(e.to_string()))
+    }
 }
 
 impl Trainer for PyTrainer {