Makes PathBuf FromPyObject implementation work on all os.PathLike

PyOS_FSPath is in abi3-py36

guide/src/conversions/tables.md

@@ -37,6 +37,7 @@ The table below contains the Python type and the corresponding function argument
 | `decimal.Decimal` | `rust_decimal::Decimal`[^5] | -                    |
 | `ipaddress.IPv4Address` | `std::net::IpAddr`, `std::net::IpV4Addr` | - |
 | `ipaddress.IPv6Address` | `std::net::IpAddr`, `std::net::IpV6Addr` | - |
+| `os.PathLike ` | `PathBuf`, `Path`              | `&PyString`, `&PyUnicode` |
 | `pathlib.Path` | `PathBuf`, `Path`              | `&PyString`, `&PyUnicode` |
 | `typing.Optional[T]` | `Option<T>`              | -                    |
 | `typing.Sequence[T]` | `Vec<T>`                 | `&PySequence`        |

newsfragments/3374.added.md

@@ -0,0 +1 @@
+`PathBuf` `FromPyObject` implementation now works on all `os.PathLike` values.

pytests/tests/test_path.py

@@ -1,5 +1,7 @@
 import pathlib
 
+import pytest
+
 import pyo3_pytests.path as rpath
 
 
@@ -16,3 +18,25 @@ def test_take_pathbuf():
 def test_take_pathlib():
     p = pathlib.Path("/root")
     assert rpath.take_pathbuf(p) == str(p)
+
+
+def test_take_pathlike():
+    assert rpath.take_pathbuf(PathLike("/root")) == "/root"
+
+
+def test_take_invalid_pathlike():
+    with pytest.raises(TypeError):
+        assert rpath.take_pathbuf(PathLike(1))
+
+
+def test_take_invalid():
+    with pytest.raises(TypeError):
+        assert rpath.take_pathbuf(3)
+
+
+class PathLike:
+    def __init__(self, path):
+        self._path = path
+
+    def __fspath__(self):
+        return self._path

src/conversions/std/path.rs

@@ -1,5 +1,7 @@
-use crate::intern;
-use crate::{FromPyObject, IntoPy, PyAny, PyObject, PyResult, Python, ToPyObject};
+use crate::{
+    ffi, AsPyPointer, FromPyObject, FromPyPointer, IntoPy, PyAny, PyObject, PyResult, Python,
+    ToPyObject,
+};
 use std::borrow::Cow;
 use std::ffi::OsString;
 use std::path::{Path, PathBuf};
@@ -14,21 +16,9 @@ impl ToPyObject for Path {
 
 impl FromPyObject<'_> for PathBuf {
     fn extract(ob: &PyAny) -> PyResult<Self> {
-        let os_str = match OsString::extract(ob) {
-            Ok(s) => s,
-            Err(err) => {
-                let py = ob.py();
-                let pathlib = py.import(intern!(py, "pathlib"))?;
-                let pathlib_path = pathlib.getattr(intern!(py, "Path"))?;
-                if ob.is_instance(pathlib_path)? {
-                    let path_str = ob.call_method0(intern!(py, "__str__"))?;
-                    OsString::extract(path_str)?
-                } else {
-                    return Err(err);
-                }
-            }
-        };
-        Ok(PathBuf::from(os_str))
+        // We use os.fspath to get the underlying path as bytes or str
+        let path = unsafe { PyAny::from_owned_ptr_or_err(ob.py(), ffi::PyOS_FSPath(ob.as_ptr())) }?;
+        Ok(OsString::extract(path)?.into())
     }
 }