refactor(python): split into multiple files

The one file was growing too big. Split it into multiple files for
easier maintenance.

eppo_core/src/context_attributes.rs

@@ -42,14 +42,13 @@ where
                         acc.numeric.insert(key.to_owned(), value);
                     }
                     AttributeValue::Boolean(value) => {
-                        // TBD: shall we ignore boolean attributes instead?
-                        //
                         // One argument for including it here is that this basically guarantees that
                         // assignment evaluation inside bandit evaluation works the same way as if
                         // `get_assignment()` was called with generic `Attributes`.
                         //
-                        // We can go a step further and remove `AttributeValue::Boolean` altogether,
-                        // forcing it to be converted to a string before any evaluation.
+                        // We can go a step further and remove `AttributeValue::Boolean` altogether
+                        // (from `eppo_core`), forcing it to be converted to a string before any
+                        // evaluation.
                         acc.categorical.insert(key.to_owned(), value.to_string());
                     }
                     AttributeValue::Null => {

eppo_core/src/pyo3.rs

@@ -1,3 +1,4 @@
+//! Helpers for Python SDK implementation.
 use pyo3::prelude::*;
 
 /// Similar to [`pyo3::ToPyObject`] but allows the conversion to fail.

python-sdk/src/assignment_logger.rs

@@ -0,0 +1,20 @@
+use pyo3::prelude::*;
+use pyo3::types::PyDict;
+
+#[derive(Debug, Clone)]
+#[pyclass(frozen, subclass, module = "eppo_client")]
+pub struct AssignmentLogger {}
+
+#[pymethods]
+impl AssignmentLogger {
+    #[new]
+    fn new() -> AssignmentLogger {
+        AssignmentLogger {}
+    }
+
+    #[allow(unused_variables)]
+    fn log_assignment(slf: Bound<Self>, event: Bound<PyDict>) {}
+
+    #[allow(unused_variables)]
+    fn log_bandit_action(slf: Bound<Self>, event: Bound<PyDict>) {}
+}