gh-101144: Allow open and read_text encoding to be positional.

Lib/test/test_zipfile/test_path.py

@@ -145,7 +145,41 @@ def test_open(self, alpharep):
         a, b, g = root.iterdir()
         with a.open(encoding="utf-8") as strm:
             data = strm.read()
-        assert data == "content of a"
+        self.assertEqual(data, "content of a")
+        with a.open('r', "utf-8") as strm:  # not a kw, no gh-101144 TypeError
+            data = strm.read()
+        self.assertEqual(data, "content of a")
+
+    def test_open_encoding_utf16(self):
+        in_memory_file = io.BytesIO()
+        zf = zipfile.ZipFile(in_memory_file, "w")
+        zf.writestr("path/16.txt", "This was utf-16".encode("utf-16"))
+        zf.filename = "test_open_utf16.zip"
+        root = zipfile.Path(zf)
+        path, = root.iterdir()
+        u16 = path.joinpath("16.txt")
+        with u16.open('r', "utf-16") as strm:
+            data = strm.read()
+        self.assertEqual(data, "This was utf-16")
+        with u16.open(encoding="utf-16") as strm:
+            data = strm.read()
+        self.assertEqual(data, "This was utf-16")
+
+    def test_read_text_encoding_errors(self):
+        in_memory_file = io.BytesIO()
+        zf = zipfile.ZipFile(in_memory_file, "w")
+        zf.writestr("path/bad-utf8.bin", b"invalid utf-8: \xff\xff.")
+        zf.filename = "test_read_text_encoding_errors.zip"
+        root = zipfile.Path(zf)
+        path, = root.iterdir()
+        u16 = path.joinpath("bad-utf8.bin")
+        with self.assertRaises(UnicodeDecodeError):
+            u16.read_text(encoding="utf-8", errors="strict")  # both keywords
+        data = u16.read_text("utf-8", errors="ignore")  # errors keyword
+        self.assertEqual(data, "invalid utf-8: .")
+        # encoding= both positional and keyword is an error; gh-101144.
+        with self.assertRaisesRegex(TypeError, "encoding"):
+            data = u16.read_text("utf-8", encoding="utf-8")
 
     def test_open_write(self):
         """
@@ -187,6 +221,7 @@ def test_read(self, alpharep):
         root = zipfile.Path(alpharep)
         a, b, g = root.iterdir()
         assert a.read_text(encoding="utf-8") == "content of a"
+        a.read_text("utf-8")  # No positional arg TypeError per gh-101144.
         assert a.read_bytes() == b"content of a"
 
     @pass_alpharep

Lib/zipfile/_path.py

@@ -257,9 +257,21 @@ def open(self, mode='r', *args, pwd=None, **kwargs):
             if args or kwargs:
                 raise ValueError("encoding args invalid for binary operation")
             return stream
-        else:
-            kwargs["encoding"] = io.text_encoding(kwargs.get("encoding"))
-        return io.TextIOWrapper(stream, *args, **kwargs)
+        # Text mode:
+        encoding = None
+        if args:
+            # Per io.TextIOWrapper, encoding is the first positional arg.
+            # Our API is to pass all *args and **kwargs to TextIOWrapper.
+            # Extract it so we can process it.
+            encoding = args[0]
+            args = args[1:]
+            # We must check this manually as we extract it for processing.
+            if "encoding" in kwargs:
+                raise TypeError(
+                        "argument ('encoding') given by name and position (1)")
+        encoding = kwargs.pop("encoding", encoding)
+        encoding = io.text_encoding(encoding)
+        return io.TextIOWrapper(stream, encoding, *args, **kwargs)
 
     @property
     def name(self):
@@ -282,7 +294,6 @@ def filename(self):
         return pathlib.Path(self.root.filename).joinpath(self.at)
 
     def read_text(self, *args, **kwargs):
-        kwargs["encoding"] = io.text_encoding(kwargs.get("encoding"))
         with self.open('r', *args, **kwargs) as strm:
             return strm.read()
 

Misc/NEWS.d/next/Library/2023-01-18-17-58-50.gh-issue-101144.FHd8Un.rst

@@ -0,0 +1,4 @@
+Make :func:`zipfile.Path.open` and :func:`zipfile.Path.read_text` also accept
+``encoding`` as a positional argument. This was the behavior in Python 3.9 and
+earlier.  3.10 introduced a regression where supplying it as a positional
+argument would lead to a :exc:`TypeError`.