Add path option for Python source

src/build_context.rs

@@ -73,22 +73,31 @@ pub enum ProjectLayout {
 
 impl ProjectLayout {
     /// Checks whether a python module exists besides Cargo.toml with the right name
-    pub fn determine(project_root: impl AsRef<Path>, module_name: &str) -> Result<ProjectLayout> {
+    pub fn determine(
+        project_root: impl AsRef<Path>,
+        module_name: &str,
+        py_src: Option<impl AsRef<Path>>,
+    ) -> Result<ProjectLayout> {
         // A dot in the module name means the extension module goes into the module folder specified by the path
         let parts: Vec<&str> = module_name.split('.').collect();
         let project_root = project_root.as_ref();
+        let python_root = if let Some(py_src) = py_src {
+            project_root.join(py_src.as_ref())
+        } else {
+            project_root.to_path_buf()
+        };
         let (python_module, rust_module, extension_name) = if parts.len() > 1 {
             let mut rust_module = project_root.to_path_buf();
             rust_module.extend(&parts[0..parts.len() - 1]);
             (
-                project_root.join(parts[0]),
+                python_root.join(parts[0]),
                 rust_module,
                 parts[parts.len() - 1].to_string(),
             )
         } else {
             (
-                project_root.join(module_name),
-                project_root.join(module_name),
+                python_root.join(module_name),
+                python_root.join(module_name),
                 module_name.to_string(),
             )
         };

src/build_options.rs

@@ -152,7 +152,8 @@ impl BuildOptions {
             .filter(|name| name.contains('.'))
             .unwrap_or(&module_name);
 
-        let project_layout = ProjectLayout::determine(manifest_dir, extension_name)?;
+        let py_src = extra_metadata.python_source.clone();
+        let project_layout = ProjectLayout::determine(manifest_dir, extension_name, py_src)?;
 
         let mut cargo_extra_args = split_extra_args(&self.cargo_extra_args)?;
         if let Some(ref target) = self.target {

src/cargo_toml.rs

@@ -123,6 +123,7 @@ pub struct RemainingCoreMetadata {
     pub project_url: Option<HashMap<String, String>>,
     pub provides_extra: Option<Vec<String>>,
     pub description_content_type: Option<String>,
+    pub python_source: Option<String>,
 }
 
 #[cfg(test)]

test-crates/pyo3-mixed-py-subdir/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+authors = ["konstin <[email protected]>"]
+name = "pyo3-mixed-py-subdir"
+version = "2.1.3"
+description = "Implements a dummy function combining rust and python"
+readme = "Readme.md"
+edition = "2018"
+
+[dependencies]
+pyo3 = { version = "0.14.0", features = ["extension-module"] }
+
+[lib]
+name = "pyo3_mixed_py_subdir"
+crate-type = ["cdylib"]
+
+[package.metadata.maturin]
+python-source = "python"

test-crates/pyo3-mixed-py-subdir/Readme.md

@@ -0,0 +1,30 @@
+# pyo3-mixed
+
+A package for testing maturin with a mixed pyo3/python project.
+
+## Usage
+
+```bash
+pip install .
+```
+
+```python
+import pyo3_mixed
+assert pyo3_mixed.get_42() == 42
+```
+
+## Testing
+
+Install tox:
+
+```bash
+pip install tox
+```
+
+Run it:
+
+```bash
+tox
+```
+
+The tests are in `test_pyo3_mixed.py`, while the configuration is in tox.ini

test-crates/pyo3-mixed-py-subdir/check_installed/check_installed.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python3
+
+import pyo3_mixed_py_subdir as pyo3_mixed
+
+assert pyo3_mixed.get_42() == 42
+
+print("SUCCESS")

test-crates/pyo3-mixed-py-subdir/pyproject.toml

@@ -0,0 +1,14 @@
+[build-system]
+requires = ["maturin>=0.11,<0.12"]
+build-backend = "maturin"
+
+[project]
+name = "pyo3-mixed-py-subdir"
+classifiers = [
+    "Programming Language :: Python",
+    "Programming Language :: Rust"
+]
+requires-python = ">=3.6"
+
+[project.scripts]
+get_42 = "pyo3_mixed_py_subdir:get_42"

test-crates/pyo3-mixed-py-subdir/python/pyo3_mixed_py_subdir/__init__.py

@@ -0,0 +1,6 @@
+from .python_module.double import double
+from .pyo3_mixed_py_subdir import get_21
+
+
+def get_42() -> int:
+    return double(get_21)

test-crates/pyo3-mixed-py-subdir/python/pyo3_mixed_py_subdir/python_module/double.py

@@ -0,0 +1,5 @@
+from typing import Callable
+
+
+def double(fn: Callable[[], int]) -> int:
+    return 2 * fn()