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'.

Lib/bz2.py

@@ -17,7 +17,7 @@ import _compression
 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 @@ class BZ2File(_compression.BaseStream):
         """
         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 @@ class BZ2File(_compression.BaseStream):
         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 @@ class BZ2File(_compression.BaseStream):
             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."""