pathlib: Add Path.expanduser().

The behaviour follows CPython.

Signed-off-by: Michael Hirsch <michael@scivision.dev>
Signed-off-by: Damien George <damien@micropython.org>

Author: scivision

python-stdlib/pathlib/manifest.py

@@ -1,3 +1,3 @@
-metadata(version="0.0.2")
+metadata(version="0.1.0")
 
 module("pathlib.py")

python-stdlib/pathlib/pathlib.py

@@ -187,6 +187,13 @@ def with_suffix(self, suffix):
         index = -len(self.suffix) or None
         return Path(self._path[:index] + suffix)
 
+    def expanduser(self):
+        if self._path == "~" or self._path.startswith("~" + _SEP):
+            return Path(os.getenv("HOME") + self._path[1:])
+        if self._path[0] == "~":
+            raise RuntimeError("user expansion not supported")
+        return self
+
     @property
     def stem(self):
         return self.name.rsplit(".", 1)[0]

python-stdlib/pathlib/tests/test_pathlib.py

@@ -339,3 +339,11 @@ def test_rtruediv_inplace(self):
         res = "foo"
         res /= Path("bar")
         self.assertTrue(res == Path("foo/bar"))
+
+    def test_expanduser(self):
+        self.assertFalse(str(Path("~").expanduser()) == "~")
+        self.assertTrue(str(Path("~").expanduser()) == os.getenv("HOME"))
+        self.assertTrue(str(Path("~/foo").expanduser()) == os.getenv("HOME") + "/foo")
+
+        with self.assertRaises(RuntimeError):
+            Path("~foo").expanduser()