gh-115961: Add name and mode attributes for compressed file-like objects (GH-116036)

* Add name and mode attributes for compressed and archived file-like objects
  in modules bz2, lzma, tarfile and zipfile.
* Change the value of the mode attribute of GzipFile from integer (1 or 2)
  to string ('rb' or 'wb').
* Change the value of the mode attribute of ZipExtFile from 'r' to 'rb'.

Author: serhiy-storchaka

Doc/library/bz2.rst

@@ -91,7 +91,7 @@ The :mod:`bz2` module contains:
    and :meth:`~io.IOBase.truncate`.
    Iteration and the :keyword:`with` statement are supported.
 
-   :class:`BZ2File` also provides the following methods:
+   :class:`BZ2File` also provides the following methods and attributes:
 
    .. method:: peek([n])
 
@@ -148,6 +148,19 @@ The :mod:`bz2` module contains:
 
       .. versionadded:: 3.3
 
+   .. attribute:: mode
+
+      ``'rb'`` for reading and ``'wb'`` for writing.
+
+      .. versionadded:: 3.13
+
+   .. attribute:: name
+
+      The bzip2 file name.  Equivalent to the :attr:`~io.FileIO.name`
+      attribute of the underlying :term:`file object`.
+
+      .. versionadded:: 3.13
+
 
    .. versionchanged:: 3.1
       Support for the :keyword:`with` statement was added.

Doc/library/gzip.rst

@@ -133,6 +133,13 @@ The module defines the following items:
 
       .. versionadded:: 3.2
 
+   .. attribute:: mode
+
+      ``'rb'`` for reading and ``'wb'`` for writing.
+
+      .. versionchanged:: 3.13
+         In previous versions it was an integer ``1`` or ``2``.
+
    .. attribute:: mtime
 
       When decompressing, this attribute is set to the last timestamp in the most
@@ -168,14 +175,14 @@ 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.
 
+   .. versionchanged:: 3.12
+      Remove the ``filename`` attribute, use the :attr:`~GzipFile.name`
+      attribute instead.
+
 
 .. function:: compress(data, compresslevel=9, *, mtime=None)
 

Doc/library/lzma.rst

@@ -104,7 +104,7 @@ Reading and writing compressed files
    and :meth:`~io.IOBase.truncate`.
    Iteration and the :keyword:`with` statement are supported.
 
-   The following method is also provided:
+   The following method and attributes are also provided:
 
    .. method:: peek(size=-1)
 
@@ -117,6 +117,20 @@ Reading and writing compressed files
          file object (e.g. if the :class:`LZMAFile` was constructed by passing a
          file object for *filename*).
 
+   .. attribute:: mode
+
+      ``'rb'`` for reading and ``'wb'`` for writing.
+
+      .. versionadded:: 3.13
+
+   .. attribute:: name
+
+      The lzma file name.  Equivalent to the :attr:`~io.FileIO.name`
+      attribute of the underlying :term:`file object`.
+
+      .. versionadded:: 3.13
+
+
    .. versionchanged:: 3.4
       Added support for the ``"x"`` and ``"xb"`` modes.
 

Doc/library/tarfile.rst

@@ -565,6 +565,10 @@ be finalized; only the internally used file object will be closed. See the
    .. versionchanged:: 3.3
       Return an :class:`io.BufferedReader` object.
 
+   .. versionchanged:: 3.13
+      The returned :class:`io.BufferedReader` object has the :attr:`!mode`
+      attribute which is always equal to ``'rb'``.
+
 .. attribute:: TarFile.errorlevel
    :type: int
 

Doc/library/zipfile.rst

@@ -301,6 +301,10 @@ ZipFile Objects
    attempting to read or write other files in the ZIP file will raise a
    :exc:`ValueError`.
 
+   In both cases the file-like object has also attributes :attr:`!name`,
+   which is equivalent to the name of a file within the archive, and
+   :attr:`!mode`, which is ``'rb'`` or ``'wb'`` depending on the input mode.
+
    When writing a file, if the file size is not known in advance but may exceed
    2 GiB, pass ``force_zip64=True`` to ensure that the header format is
    capable of supporting large files.  If the file size is known in advance,
@@ -325,6 +329,12 @@ ZipFile Objects
       Calling :meth:`.open` on a closed ZipFile will raise a :exc:`ValueError`.
       Previously, a :exc:`RuntimeError` was raised.
 
+   .. versionchanged:: 3.13
+      Added attributes :attr:`!name` and :attr:`!mode` for the writeable
+      file-like object.
+      The value of the :attr:`!mode` attribute for the readable file-like
+      object was changed from ``'r'`` to ``'rb'``.
+
 
 .. method:: ZipFile.extract(member, path=None, pwd=None)
 

Doc/whatsnew/3.13.rst

@@ -206,6 +206,11 @@ Other Language Changes
 
   (Contributed by Victor Stinner in :gh:`114570`.)
 
+* Added :attr:`!name` and :attr:`!mode` attributes for compressed
+  and archived file-like objects in modules :mod:`bz2`, :mod:`lzma`,
+  :mod:`tarfile` and :mod:`zipfile`.
+  (Contributed by Serhiy Storchaka in :gh:`115961`.)
+
 * Allow controlling Expat >=2.6.0 reparse deferral (:cve:`2023-52425`)
   by adding five new methods:
 
@@ -1605,6 +1610,12 @@ Changes in the Python API
   than directories only. Users may add a trailing slash to match only
   directories.
 
+* The value of the :attr:`!mode` attribute of :class:`gzip.GzipFile` was
+  changed from integer (``1`` or ``2``) to string (``'rb'`` or ``'wb'``).
+  The value of the :attr:`!mode` attribute of the readable file-like object
+  returned by :meth:`zipfile.ZipFile.open` was changed from ``'r'`` to ``'rb'``.
+  (Contributed by Serhiy Storchaka in :gh:`115961`.)
+
 * :c:func:`!PyCode_GetFirstFree` is an unstable API now and has been renamed
   to :c:func:`PyUnstable_Code_GetFirstFree`.
   (Contributed by Bogdan Romanyuk in :gh:`115781`.)

Lib/bz2.py

@@ -17,7 +17,7 @@
 from _bz2 import BZ2Compressor, BZ2Decompressor
 
 
-_MODE_CLOSED   = 0
+# Value 0 no longer used
 _MODE_READ     = 1
 # Value 2 no longer used
 _MODE_WRITE    = 3
@@ -54,7 +54,7 @@ def __init__(self, filename, mode="r", *, compresslevel=9):
         """
         self._fp = None
         self._closefp = False
-        self._mode = _MODE_CLOSED
+        self._mode = None
 
         if not (1 <= compresslevel <= 9):
             raise ValueError("compresslevel must be between 1 and 9")
@@ -100,7 +100,7 @@ def close(self):
         May be called more than once without error. Once the file is
         closed, any other operation on it will raise a ValueError.
         """
-        if self._mode == _MODE_CLOSED:
+        if self.closed:
             return
         try:
             if self._mode == _MODE_READ:
@@ -115,13 +115,21 @@ def close(self):
             finally:
                 self._fp = None
                 self._closefp = False
-                self._mode = _MODE_CLOSED
                 self._buffer = None
 
     @property
     def closed(self):
         """True if this file is closed."""
-        return self._mode == _MODE_CLOSED
+        return self._fp is None
+
+    @property
+    def name(self):
+        self._check_not_closed()
+        return self._fp.name
+
+    @property
+    def mode(self):
+        return 'wb' if self._mode == _MODE_WRITE else 'rb'
 
     def fileno(self):
         """Return the file descriptor for the underlying file."""

Lib/gzip.py

@@ -15,7 +15,8 @@
 
 FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
 
-READ, WRITE = 1, 2
+READ = 'rb'
+WRITE = 'wb'
 
 _COMPRESS_LEVEL_FAST = 1
 _COMPRESS_LEVEL_TRADEOFF = 6

Lib/lzma.py

@@ -29,7 +29,7 @@
 import _compression
 
 
-_MODE_CLOSED   = 0
+# Value 0 no longer used
 _MODE_READ     = 1
 # Value 2 no longer used
 _MODE_WRITE    = 3
@@ -92,7 +92,7 @@ def __init__(self, filename=None, mode="r", *,
         """
         self._fp = None
         self._closefp = False
-        self._mode = _MODE_CLOSED
+        self._mode = None
 
         if mode in ("r", "rb"):
             if check != -1:
@@ -137,7 +137,7 @@ def close(self):
         May be called more than once without error. Once the file is
         closed, any other operation on it will raise a ValueError.
         """
-        if self._mode == _MODE_CLOSED:
+        if self.closed:
             return
         try:
             if self._mode == _MODE_READ:
@@ -153,12 +153,20 @@ def close(self):
             finally:
                 self._fp = None
                 self._closefp = False
-                self._mode = _MODE_CLOSED
 
     @property
     def closed(self):
         """True if this file is closed."""
-        return self._mode == _MODE_CLOSED
+        return self._fp is None
+
+    @property
+    def name(self):
+        self._check_not_closed()
+        return self._fp.name
+
+    @property
+    def mode(self):
+        return 'wb' if self._mode == _MODE_WRITE else 'rb'
 
     def fileno(self):
         """Return the file descriptor for the underlying file."""

Lib/tarfile.py

@@ -636,6 +636,10 @@ def __init__(self, fileobj, offset, size, name, blockinfo=None):
     def flush(self):
         pass
 
+    @property
+    def mode(self):
+        return 'rb'
+
     def readable(self):
         return True