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

As was the behavior in 3.9 and earlier.  The fix for
python#87817 introduced an API
regression in 3.10.0b1.

Author: gpshead

Lib/test/test_zipfile/test_path.py

@@ -145,7 +145,10 @@ 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:  # No gh-101144 TypeError
+            data = strm.read()
+        self.assertEqual(data, "content of a")
 
     def test_open_write(self):
         """
@@ -187,6 +190,7 @@ 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 TypeError per gh-101144.
         assert a.read_bytes() == b"content of a"
 
     @pass_alpharep

Lib/zipfile/_path.py

@@ -258,7 +258,8 @@ def open(self, mode='r', *args, pwd=None, **kwargs):
                 raise ValueError("encoding args invalid for binary operation")
             return stream
         else:
-            kwargs["encoding"] = io.text_encoding(kwargs.get("encoding"))
+            if "encoding" in kwargs:
+                kwargs["encoding"] = io.text_encoding(kwargs["encoding"])
         return io.TextIOWrapper(stream, *args, **kwargs)
 
     @property
@@ -282,7 +283,8 @@ 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"))
+        if "encoding" in kwargs:
+            kwargs["encoding"] = io.text_encoding(kwargs["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 @@
+:func:`zipfile.Path.open` and :func:`zipfile.Path.read_text` accept
+``encoding`` as a positional argument. This was the behavior in Python 3.9 and
+earlier.  3.10 introduced an unintended regression where supplying it as a
+positional argument would lead to a :exc:`TypeError`.