feat: implement python-sdk

Cargo.toml

@@ -3,6 +3,7 @@ resolver = "2"
 members = [
   "eppo_core",
   "rust-sdk",
+  "python-sdk",
   "ruby-sdk/ext/eppo_client",
 ]
 

eppo_core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "eppo_core"
-version = "2.0.0"
+version = "2.1.0"
 edition = "2021"
 description = "Eppo SDK core library"
 repository = "https://github.com/Eppo-exp/rust-sdk"
@@ -9,6 +9,10 @@ keywords = ["eppo", "feature-flags"]
 categories = ["config"]
 rust-version = "1.71.1"
 
+[features]
+# Add implementation of `FromPyObject`/`ToPyObject` for some types.
+pyo3 = ["dep:pyo3", "dep:serde-pyobject"]
+
 [dependencies]
 chrono = { version = "0.4.38", features = ["serde"] }
 derive_more = "0.99.17"
@@ -23,6 +27,10 @@ serde_json = "1.0.116"
 thiserror = "1.0.60"
 url = "2.5.0"
 
+# pyo3 dependencies
+pyo3 = { version = "0.22.0", optional = true, default-features = false }
+serde-pyobject = { version = "0.4.0", optional = true}
+
 [dev-dependencies]
 criterion = { version = "0.4", features = ["html_reports"] }
 env_logger = "0.11.3"

eppo_core/src/attributes.rs

@@ -46,3 +46,34 @@ impl From<&str> for AttributeValue {
         Self::String(value.to_owned())
     }
 }
+
+#[cfg(feature = "pyo3")]
+mod pyo3_impl {
+    use pyo3::{exceptions::PyTypeError, prelude::*, types::*};
+
+    use super::*;
+
+    impl<'py> FromPyObject<'py> for AttributeValue {
+        fn extract_bound(value: &Bound<'py, PyAny>) -> PyResult<AttributeValue> {
+            if let Ok(s) = value.downcast::<PyString>() {
+                return Ok(AttributeValue::String(s.extract()?));
+            }
+            // In Python, Bool inherits from Int, so it must be checked first here.
+            if let Ok(s) = value.downcast::<PyBool>() {
+                return Ok(AttributeValue::Boolean(s.extract()?));
+            }
+            if let Ok(s) = value.downcast::<PyFloat>() {
+                return Ok(AttributeValue::Number(s.extract()?));
+            }
+            if let Ok(s) = value.downcast::<PyInt>() {
+                return Ok(AttributeValue::Number(s.extract()?));
+            }
+            if let Ok(_) = value.downcast::<PyNone>() {
+                return Ok(AttributeValue::Null);
+            }
+            Err(PyTypeError::new_err(
+                "invalid type for subject attribute value",
+            ))
+        }
+    }
+}

eppo_core/src/eval/eval_details.rs

@@ -243,3 +243,20 @@ impl From<EvaluationError> for BanditEvaluationCode {
         }
     }
 }
+
+#[cfg(feature = "pyo3")]
+mod pyo3_impl {
+    use pyo3::prelude::*;
+
+    use crate::pyo3::TryToPyObject;
+
+    use super::EvaluationDetails;
+
+    impl TryToPyObject for EvaluationDetails {
+        fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+            serde_pyobject::to_pyobject(py, self)
+                .map(|it| it.unbind())
+                .map_err(|err| err.0)
+        }
+    }
+}

eppo_core/src/events.rs

@@ -62,3 +62,20 @@ pub struct BanditEvent {
     pub action_categorical_attributes: HashMap<String, String>,
     pub meta_data: HashMap<String, String>,
 }
+
+#[cfg(feature = "pyo3")]
+mod pyo3_impl {
+    use pyo3::{PyObject, PyResult, Python};
+
+    use crate::pyo3::TryToPyObject;
+
+    use super::AssignmentEvent;
+
+    impl TryToPyObject for AssignmentEvent {
+        fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+            serde_pyobject::to_pyobject(py, self)
+                .map(|it| it.unbind())
+                .map_err(|err| err.0)
+        }
+    }
+}

eppo_core/src/lib.rs

@@ -20,6 +20,8 @@ pub mod configuration_store;
 pub mod eval;
 pub mod events;
 pub mod poller_thread;
+#[cfg(feature = "pyo3")]
+pub mod pyo3;
 pub mod sharder;
 pub mod ufc;
 

eppo_core/src/pyo3.rs

@@ -0,0 +1,30 @@
+use pyo3::prelude::*;
+
+/// Similar to [`pyo3::ToPyObject`] but allows the conversion to fail.
+pub trait TryToPyObject {
+    fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject>;
+}
+
+// Implementing on `&T` to allow dtolnay specialization[1] (e.g., for `Option<T>` below).
+//
+// [1]: https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md
+impl<T: ToPyObject> TryToPyObject for &T {
+    fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+        Ok(self.to_object(py))
+    }
+}
+
+impl<T> TryToPyObject for Py<T> {
+    fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+        Ok(self.to_object(py))
+    }
+}
+
+impl<T: TryToPyObject> TryToPyObject for Option<T> {
+    fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+        match self {
+            Some(it) => it.try_to_pyobject(py),
+            None => Ok(().to_object(py)),
+        }
+    }
+}

eppo_core/src/ufc/assignment.rs

@@ -230,3 +230,28 @@ impl AssignmentValue {
         }
     }
 }
+
+#[cfg(feature = "pyo3")]
+mod pyo3_impl {
+    use pyo3::prelude::*;
+
+    use crate::pyo3::TryToPyObject;
+
+    use super::*;
+
+    impl TryToPyObject for AssignmentValue {
+        fn try_to_pyobject(&self, py: Python) -> PyResult<PyObject> {
+            let obj = match self {
+                AssignmentValue::String(s) => s.to_object(py),
+                AssignmentValue::Integer(i) => i.to_object(py),
+                AssignmentValue::Numeric(n) => n.to_object(py),
+                AssignmentValue::Boolean(b) => b.to_object(py),
+                AssignmentValue::Json(j) => match serde_pyobject::to_pyobject(py, j) {
+                    Ok(it) => it.unbind(),
+                    Err(err) => return Err(err.0),
+                },
+            };
+            Ok(obj)
+        }
+    }
+}

package.json

@@ -3,6 +3,7 @@
   "scripts": {
     "test": "npm run with-server 'npm-run-all test:*'",
     "test:rust": "cargo test",
+    "test:python": "cd python-sdk && maturin develop && pytest",
     "test:ruby": "cd ruby-sdk && bundle exec rake test",
     "with-server": "start-server-and-test start-mock-server http://127.0.0.1:8378",
     "start-mock-server": "npm start --prefix ./mock-server"

python-sdk/.gitignore

@@ -0,0 +1,72 @@
+/target
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+.pytest_cache/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+.venv/
+env/
+bin/
+build/
+develop-eggs/
+dist/
+eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+include/
+man/
+venv/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+pip-selfcheck.json
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+
+# Rope
+.ropeproject
+
+# Django stuff:
+*.log
+*.pot
+
+.DS_Store
+
+# Sphinx documentation
+docs/_build/
+
+# PyCharm
+.idea/
+
+# VSCode
+.vscode/
+
+# Pyenv
+.python-version

python-sdk/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "eppo_py"
+version = "5.0.0"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+eppo_core = { version = "2.1.0", features = ["pyo3"] }
+log = "0.4.22"
+pyo3 = { version = "0.22.0" }
+pyo3-log = "0.11.0"
+serde-pyobject = "0.4.0"

python-sdk/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Eppo
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.