Issue #21127: Path objects can now be instantiated from str subclass instances (such as numpy.str_).
Thanks to Antony Lee for the report and preliminary patch.
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 8d08e8b..d3d1af8 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -574,8 +574,8 @@
if isinstance(a, PurePath):
parts += a._parts
elif isinstance(a, str):
- # Assuming a str
- parts.append(a)
+ # Force-cast str subclasses to str (issue #21127)
+ parts.append(str(a))
else:
raise TypeError(
"argument should be a path or str object, not %r"
diff --git a/Lib/test/test_pathlib.py b/Lib/test/test_pathlib.py
index 2268f94..6378d8c 100644
--- a/Lib/test/test_pathlib.py
+++ b/Lib/test/test_pathlib.py
@@ -197,6 +197,25 @@
self.assertEqual(P(P('a'), 'b'), P('a/b'))
self.assertEqual(P(P('a'), P('b')), P('a/b'))
+ def _check_str_subclass(self, *args):
+ # Issue #21127: it should be possible to construct a PurePath object
+ # from an str subclass instance, and it then gets converted to
+ # a pure str object.
+ class StrSubclass(str):
+ pass
+ P = self.cls
+ p = P(*(StrSubclass(x) for x in args))
+ self.assertEqual(p, P(*args))
+ for part in p.parts:
+ self.assertIs(type(part), str)
+
+ def test_str_subclass_common(self):
+ self._check_str_subclass('')
+ self._check_str_subclass('.')
+ self._check_str_subclass('a')
+ self._check_str_subclass('a/b.txt')
+ self._check_str_subclass('/a/b.txt')
+
def test_join_common(self):
P = self.cls
p = P('a/b')
@@ -690,6 +709,17 @@
p = self.cls('//a/b/c/d')
self.assertEqual(str(p), '\\\\a\\b\\c\\d')
+ def test_str_subclass(self):
+ self._check_str_subclass('c:')
+ self._check_str_subclass('c:a')
+ self._check_str_subclass('c:a\\b.txt')
+ self._check_str_subclass('c:\\')
+ self._check_str_subclass('c:\\a')
+ self._check_str_subclass('c:\\a\\b.txt')
+ self._check_str_subclass('\\\\some\\share')
+ self._check_str_subclass('\\\\some\\share\\a')
+ self._check_str_subclass('\\\\some\\share\\a\\b.txt')
+
def test_eq(self):
P = self.cls
self.assertEqual(P('c:a/b'), P('c:a/b'))
diff --git a/Misc/ACKS b/Misc/ACKS
index 4173917..6064bfd 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -743,6 +743,7 @@
Chris Lawrence
Brian Leair
Mathieu Leduc-Hamel
+Antony Lee
Christopher Lee
Inyeol Lee
James Lee
diff --git a/Misc/NEWS b/Misc/NEWS
index fcdaabf..332c7ef 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -39,6 +39,9 @@
Library
-------
+- Issue #21127: Path objects can now be instantiated from str subclass
+ instances (such as numpy.str_).
+
- Issue #15002: urllib.response object to use _TemporaryFileWrapper (and
_TemporaryFileCloser) facility. Provides a better way to handle file
descriptor close. Patch contributed by Christian Theune.