add python wrapper

Makefile

@@ -10,4 +10,4 @@ cov:
 
 .PHONY: py
 py:
-	maturin develop
+	rye run maturin develop --pip-path ~/.rye/self/bin/pip

pyproject.toml

@@ -1,10 +1,13 @@
+[tool.rye.scripts]
+check = "pyright"
+test = "pytest"
+
 [build-system]
 requires = ["maturin>=1.5,<2.0"]
 build-backend = "maturin"
 
 [project]
 name = "bean-rs"
-requires-python = ">= 3.9"
 classifiers = [
   "Environment :: Console",
   "License :: OSI Approved :: MIT License",
@@ -15,5 +18,53 @@ classifiers = [
 ]
 dynamic = ["version"]
 
+requires-python = ">= 3.9"
+
+dependencies = [
+]
+
+[project.urls]
+homepage = "https://github.com/carderne/signal-export"
+repository = "https://github.com/carderne/signal-export"
+
+[tool.rye]
+managed = true
+dev-dependencies = [
+    "maturin>=1.5,<2.0",
+    "pyright",
+    "pytest",
+]
+
 [tool.maturin]
+python-source = "python"
+module-name = "bean_rs._bean_rs"
 features = ["pyo3/extension-module"]
+
+[tool.ruff]
+target-version = "py39"
+
+[tool.ruff.lint]
+select = [
+    "F",
+    "E",
+    "I",
+    "U",
+    "N",
+    "E",
+    "T100",
+    "A",
+    "Q",
+    "ANN",
+]
+
+[tool.pyright]
+venvPath = "."
+venv = ".venv"
+extraPaths = ["./python/bean_rs"]
+include = ["python"]
+reportMissingImports = true
+reportMissingParameterType = true
+reportUnnecessaryTypeIgnoreComment = true
+reportDeprecated = true
+pythonVersion = "3.12"
+pythonPlatform = "Linux"

python/bean_rs/__init__.py

@@ -0,0 +1,7 @@
+"""Python binds to a beancount clone in Rust."""
+
+# The Rust bindings are in `_bean_rs` and we try to mediate all access
+# through this file to make typing a bit easier
+from bean_rs._bean_rs import load
+
+__all__ = ["load"]

python/bean_rs/bean_rs.pyi

@@ -0,0 +1,19 @@
+import datetime
+
+class Options:
+    title: str
+    operating_currency: str
+
+class BeanError(Exception):
+    pass
+
+class Directive:
+    date: datetime.date
+
+class Ledger:
+    dirs: list[Directive]
+    errs: list[BeanError]
+    opts: Options
+
+def load(path: str) -> Ledger:
+    pass

python/tests/test_load.py

@@ -0,0 +1,6 @@
+from bean_rs import load
+
+
+def test_load() -> None:
+    ledger = load("example.bean")
+    assert ledger.opts.operating_currency == "GBP"

requirements-dev.lock

@@ -0,0 +1,23 @@
+# generated by rye
+# use `rye lock` or `rye sync` to update this lockfile
+#
+# last locked with the following flags:
+#   pre: false
+#   features: []
+#   all-features: false
+#   with-sources: false
+
+-e file:.
+iniconfig==2.0.0
+    # via pytest
+maturin==1.5.1
+nodeenv==1.8.0
+    # via pyright
+packaging==24.0
+    # via pytest
+pluggy==1.4.0
+    # via pytest
+pyright==1.1.358
+pytest==8.1.1
+setuptools==69.5.1
+    # via nodeenv

requirements.lock

@@ -0,0 +1,10 @@
+# generated by rye
+# use `rye lock` or `rye sync` to update this lockfile
+#
+# last locked with the following flags:
+#   pre: false
+#   features: []
+#   all-features: false
+#   with-sources: false
+
+-e file:.

src/error.rs

@@ -1,3 +1,4 @@
+use pyo3::pyclass;
 use std::fmt;
 
 use crate::data::{DebugLine, Directive};
@@ -16,10 +17,10 @@ pub enum ErrorType {
     InvalidCcy,
 }
 
-#[allow(dead_code)]
-#[derive(Debug)]
+#[pyclass]
+#[derive(Clone, Debug)]
 pub struct BeanError {
-    pub ty: ErrorType, // not yet used anywhere
+    pub ty: ErrorType,
     pub debug: DebugLine,
     pub msg: String,
 }

src/ledger.rs

@@ -6,6 +6,7 @@ use crate::error::BeanError;
 #[pyclass]
 pub struct Ledger {
     pub dirs: Vec<Directive>,
+    #[pyo3(get)]
     pub errs: Vec<BeanError>,
     #[pyo3(get)]
     pub opts: Options,

src/lib.rs

@@ -45,14 +45,15 @@ pub fn balance(path: &str) -> (AccBal, Vec<BeanError>) {
 
 /// Load the ledger from Python
 #[pyfunction]
+#[pyo3(name = "load")]
 fn py_load(path: &str) -> Ledger {
     let text = std::fs::read_to_string(path).expect("cannot read file");
     load(text)
 }
 
-/// `bean_rs` importable from Python
+/// `_bean_rs` importable from Python
 #[pymodule]
-fn bean_rs(m: &Bound<'_, PyModule>) -> PyResult<()> {
+fn _bean_rs(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(py_load, m)?)?;
     Ok(())
 }