bpo-30218: support path-like objects in shutil.unpack_archive() (GH-1367)

Thanks to Jelle Zijlstra for the patch.

Doc/library/shutil.rst

@@ -550,6 +550,9 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
    registered for that extension.  In case none is found,
    a :exc:`ValueError` is raised.
 
+   .. versionchanged:: 3.7
+      Accepts a :term:`path-like object` for *filename* and *extract_dir*.
+
 
 .. function:: register_unpack_format(name, extensions, function[, extra_args[, description]])
 

Lib/shutil.py

@@ -958,6 +958,9 @@ def unpack_archive(filename, extract_dir=None, format=None):
     if extract_dir is None:
         extract_dir = os.getcwd()
 
+    extract_dir = os.fspath(extract_dir)
+    filename = os.fspath(filename)
+
     if format is not None:
         try:
             format_info = _UNPACK_FORMATS[format]

Lib/test/test_shutil.py

@@ -10,6 +10,7 @@ import os
 import os.path
 import errno
 import functools
+import pathlib
 import subprocess
 from shutil import (make_archive,
                     register_archive_format, unregister_archive_format,
@@ -1223,6 +1224,18 @@ class TestShutil(unittest.TestCase):
         self.assertNotIn('xxx', formats)
 
     def check_unpack_archive(self, format):
+        self.check_unpack_archive_with_converter(format, lambda path: path)
+        self.check_unpack_archive_with_converter(format, pathlib.Path)
+
+        class MyPath:
+            def __init__(self, path):
+                self.path = path
+            def __fspath__(self):
+                return self.path
+
+        self.check_unpack_archive_with_converter(format, MyPath)
+
+    def check_unpack_archive_with_converter(self, format, converter):
         root_dir, base_dir = self._create_files()
         expected = rlistdir(root_dir)
         expected.remove('outer')
@@ -1232,16 +1245,16 @@ class TestShutil(unittest.TestCase):
 
         # let's try to unpack it now
         tmpdir2 = self.mkdtemp()
-        unpack_archive(filename, tmpdir2)
+        unpack_archive(converter(filename), converter(tmpdir2))
         self.assertEqual(rlistdir(tmpdir2), expected)
 
         # and again, this time with the format specified
         tmpdir3 = self.mkdtemp()
-        unpack_archive(filename, tmpdir3, format=format)
+        unpack_archive(converter(filename), converter(tmpdir3), format=format)
         self.assertEqual(rlistdir(tmpdir3), expected)
 
-        self.assertRaises(shutil.ReadError, unpack_archive, TESTFN)
+        self.assertRaises(shutil.ReadError, unpack_archive, converter(TESTFN))
-        self.assertRaises(ValueError, unpack_archive, TESTFN, format='xxx')
+        self.assertRaises(ValueError, unpack_archive, converter(TESTFN), format='xxx')
 
     def test_unpack_archive_tar(self):
         self.check_unpack_archive('tar')

Misc/NEWS

@@ -362,6 +362,9 @@ Library
   Fixed possible other errors caused by not checking results of PyObject_Size(),
   PySequence_Size(), or PyMapping_Size().
 
+- bpo-30218: Fix PathLike support for shutil.unpack_archive. Patch by Jelle
+  Zijlstra.
+
 - bpo-10076: Compiled regular expression and match objects in the re module
   now support copy.copy() and copy.deepcopy() (they are considered atomic).