gh-94196: Remove gzip.GzipFile.filename attribute (#94197)

gzip: Remove the filename attribute of gzip.GzipFile,
deprecated since Python 2.6, use the name attribute instead. In write
mode, the filename attribute added '.gz' file extension if it was not
present.

Doc/library/gzip.rst

@@ -165,6 +165,10 @@ The module defines the following items:
    .. versionchanged:: 3.6
       Accepts a :term:`path-like object`.
 
+   .. versionchanged:: 3.12
+      Remove the ``filename`` attribute, use the :attr:`~GzipFile.name`
+      attribute instead.
+
    .. deprecated:: 3.9
       Opening :class:`GzipFile` for writing without specifying the *mode*
       argument is deprecated.

Doc/whatsnew/3.12.rst

@@ -218,6 +218,12 @@ Removed
   use :func:`os.urandom` or :func:`ssl.RAND_bytes` instead.
   (Contributed by Victor Stinner in :gh:`94199`.)
 
+* :mod:`gzip`: Remove the ``filename`` attribute of :class:`gzip.GzipFile`,
+  deprecated since Python 2.6, use the :attr:`~gzip.GzipFile.name` attribute
+  instead. In write mode, the ``filename`` attribute added ``'.gz'`` file
+  extension if it was not present.
+  (Contributed by Victor Stinner in :gh:`94196`.)
+
 
 Porting to Python 3.12
 ======================

Lib/gzip.py

@@ -212,14 +212,6 @@ class GzipFile(_compression.BaseStream):
         if self.mode == WRITE:
             self._write_gzip_header(compresslevel)
 
-    @property
-    def filename(self):
-        import warnings
-        warnings.warn("use the name attribute", DeprecationWarning, 2)
-        if self.mode == WRITE and self.name[-3:] != ".gz":
-            return self.name + ".gz"
-        return self.name
-
     @property
     def mtime(self):
         """Last modification time read from stream, or None"""

Misc/NEWS.d/next/Library/2022-06-24-09-41-41.gh-issue-94196.r2KyfS.rst

@@ -0,0 +1,4 @@
+:mod:`gzip`: Remove the ``filename`` attribute of :class:`gzip.GzipFile`,
+deprecated since Python 2.6, use the :attr:`~gzip.GzipFile.name` attribute
+instead. In write mode, the ``filename`` attribute added ``'.gz'`` file
+extension if it was not present. Patch by Victor Stinner.