Add support for extracting PathBuf from pathlib.Path

CHANGELOG.md

@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Add `#[pyo3(name = "...")]` syntax for setting Python names. [#1567](https://github.com/PyO3/pyo3/pull/1567)
 - Add FFI definition `PyDateTime_TimeZone_UTC`. [#1572](https://github.com/PyO3/pyo3/pull/1572)
 - Add support for `#[pyclass(extends=Exception)]`. [#1591](https://github.com/PyO3/pyo3/pull/1591)
+- Add support for extracting `PathBuf` from `pathlib.Path`. [#1654](https://github.com/PyO3/pyo3/pull/1654)
 
 ### Changed
 - Allow only one `#[pymethods]` block per `#[pyclass]` by default, to simplify the proc macro implementations. Add `multiple-pymethods` feature to opt-in to the more complex full behavior. [#1457](https://github.com/PyO3/pyo3/pull/1457)

examples/pyo3-pytests/src/lib.rs

@@ -8,6 +8,7 @@ pub mod dict_iter;
 pub mod misc;
 pub mod objstore;
 pub mod othermod;
+pub mod path;
 pub mod pyclass_iter;
 pub mod subclassing;
 
@@ -17,6 +18,7 @@ use dict_iter::*;
 use misc::*;
 use objstore::*;
 use othermod::*;
+use path::*;
 use pyclass_iter::*;
 use subclassing::*;
 
@@ -28,6 +30,7 @@ fn pyo3_pytests(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_wrapped(wrap_pymodule!(misc))?;
     m.add_wrapped(wrap_pymodule!(objstore))?;
     m.add_wrapped(wrap_pymodule!(othermod))?;
+    m.add_wrapped(wrap_pymodule!(path))?;
     m.add_wrapped(wrap_pymodule!(pyclass_iter))?;
     m.add_wrapped(wrap_pymodule!(subclassing))?;
 
@@ -42,6 +45,7 @@ fn pyo3_pytests(py: Python, m: &PyModule) -> PyResult<()> {
     sys_modules.set_item("pyo3_pytests.misc", m.getattr("misc")?)?;
     sys_modules.set_item("pyo3_pytests.objstore", m.getattr("objstore")?)?;
     sys_modules.set_item("pyo3_pytests.othermod", m.getattr("othermod")?)?;
+    sys_modules.set_item("pyo3_pytests.path", m.getattr("path")?)?;
     sys_modules.set_item("pyo3_pytests.pyclass_iter", m.getattr("pyclass_iter")?)?;
     sys_modules.set_item("pyo3_pytests.subclassing", m.getattr("subclassing")?)?;
 

examples/pyo3-pytests/src/path.rs

@@ -0,0 +1,21 @@
+use pyo3::prelude::*;
+use pyo3::wrap_pyfunction;
+use std::path::{Path, PathBuf};
+
+#[pyfunction]
+fn make_path() -> PathBuf {
+    Path::new("/root").to_owned()
+}
+
+#[pyfunction]
+fn take_pathbuf(path: PathBuf) -> PathBuf {
+    path
+}
+
+#[pymodule]
+fn path(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(make_path, m)?)?;
+    m.add_function(wrap_pyfunction!(take_pathbuf, m)?)?;
+
+    Ok(())
+}

examples/pyo3-pytests/tests/test_path.py

@@ -0,0 +1,18 @@
+import pathlib
+
+import pyo3_pytests.path as rpath
+
+
+def test_make_path():
+    p = rpath.make_path()
+    assert p == "/root"
+
+
+def test_take_pathbuf():
+    p = "/root"
+    assert rpath.take_pathbuf(p) == p
+
+
+def test_take_pathlib():
+    p = pathlib.Path("/root")
+    assert rpath.take_pathbuf(p) == str(p)

src/conversions/path.rs

@@ -1,4 +1,5 @@
-use crate::{FromPyObject, IntoPy, PyAny, PyObject, PyResult, Python, ToPyObject};
+use crate::types::PyType;
+use crate::{FromPyObject, IntoPy, PyAny, PyNativeType, PyObject, PyResult, Python, ToPyObject};
 use std::borrow::Cow;
 use std::ffi::OsString;
 use std::path::{Path, PathBuf};
@@ -13,7 +14,21 @@ impl ToPyObject for Path {
 
 impl FromPyObject<'_> for PathBuf {
     fn extract(ob: &PyAny) -> PyResult<Self> {
-        Ok(PathBuf::from(OsString::extract(ob)?))
+        let os_str = match OsString::extract(ob) {
+            Ok(s) => s,
+            Err(err) => {
+                let py = ob.py();
+                let pathlib = py.import("pathlib")?;
+                let pathlib_path: &PyType = pathlib.getattr("Path")?.downcast()?;
+                if pathlib_path.is_instance(ob)? {
+                    let path_str = ob.call_method0("__str__")?;
+                    OsString::extract(path_str)?
+                } else {
+                    return Err(err);
+                }
+            }
+        };
+        Ok(PathBuf::from(os_str))
     }
 }