Issue #28225: bz2 module now supports pathlib

Initial patch by Ethan Furman.

4 files changed, 25 insertions, 7 deletions

diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst
index 6c49d9fffe..d5f622515a 100644
--- a/Doc/library/bz2.rst
+++ b/Doc/library/bz2.rst
@@ -61,6 +61,9 @@ All of the classes in this module may safely be accessed from multiple threads.
    .. versionchanged:: 3.4
       The ``'x'`` (exclusive creation) mode was added.
 
+   .. versionchanged:: 3.6
+      Accepts a :term:`path-like object`.
+
 
 .. class:: BZ2File(filename, mode='r', buffering=None, compresslevel=9)
 
@@ -128,6 +131,9 @@ All of the classes in this module may safely be accessed from multiple threads.
       The :meth:`~io.BufferedIOBase.read` method now accepts an argument of
       ``None``.
 
+   .. versionchanged:: 3.6
+      Accepts a :term:`path-like object`.
+
 
 Incremental (de)compression
 ---------------------------
diff --git a/Lib/bz2.py b/Lib/bz2.py
index bc78c54485..6f56328b9b 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -11,6 +11,7 @@ __author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>"
 
 from builtins import open as _builtin_open
 import io
+import os
 import warnings
 import _compression
 
@@ -42,9 +43,9 @@ class BZ2File(_compression.BaseStream):
     def __init__(self, filename, mode="r", buffering=None, compresslevel=9):
         """Open a bzip2-compressed file.
 
-        If filename is a str or bytes object, it gives the name
-        of the file to be opened. Otherwise, it should be a file object,
-        which will be used to read or write the compressed data.
+        If filename is a str, bytes, or PathLike object, it gives the
+        name of the file to be opened. Otherwise, it should be a file
+        object, which will be used to read or write the compressed data.
 
         mode can be 'r' for reading (default), 'w' for (over)writing,
         'x' for creating exclusively, or 'a' for appending. These can
@@ -91,7 +92,7 @@ class BZ2File(_compression.BaseStream):
         else:
             raise ValueError("Invalid mode: %r" % (mode,))
 
-        if isinstance(filename, (str, bytes)):
+        if isinstance(filename, (str, bytes, os.PathLike)):
             self._fp = _builtin_open(filename, mode)
             self._closefp = True
             self._mode = mode_code
@@ -99,7 +100,7 @@ class BZ2File(_compression.BaseStream):
             self._fp = filename
             self._mode = mode_code
         else:
-            raise TypeError("filename must be a str or bytes object, or a file")
+            raise TypeError("filename must be a str, bytes, file or PathLike object")
 
         if self._mode == _MODE_READ:
             raw = _compression.DecompressReader(self._fp,
@@ -289,8 +290,9 @@ def open(filename, mode="rb", compresslevel=9,
          encoding=None, errors=None, newline=None):
     """Open a bzip2-compressed file in binary or text mode.
 
-    The filename argument can be an actual filename (a str or bytes
-    object), or an existing file object to read from or write to.
+    The filename argument can be an actual filename (a str, bytes, or
+    PathLike object), or an existing file object to read from or write
+    to.
 
     The mode argument can be "r", "rb", "w", "wb", "x", "xb", "a" or
     "ab" for binary mode, or "rt", "wt", "xt" or "at" for text mode.
diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 46ad2c44d8..482242c00e 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -6,6 +6,7 @@ from io import BytesIO, DEFAULT_BUFFER_SIZE
 import os
 import pickle
 import glob
+import pathlib
 import random
 import subprocess
 import sys
@@ -560,6 +561,13 @@ class BZ2FileTest(BaseTest):
         with BZ2File(str_filename, "rb") as f:
             self.assertEqual(f.read(), self.DATA)
 
+    def testOpenPathLikeFilename(self):
+        filename = pathlib.Path(self.filename)
+        with BZ2File(filename, "wb") as f:
+            f.write(self.DATA)
+        with BZ2File(filename, "rb") as f:
+            self.assertEqual(f.read(), self.DATA)
+
     def testDecompressLimited(self):
         """Decompressed data buffering should be limited"""
         bomb = bz2.compress(b'\0' * int(2e6), compresslevel=9)
diff --git a/Misc/NEWS b/Misc/NEWS
index abf9c93dfb..bc4aa8c281 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -46,6 +46,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #28225: bz2 module now supports pathlib.  Initial patch by Ethan Furman.
+
 - Issue #28227: gzip now supports pathlib.  Patch by Ethan Furman.
 
 - Issue #27358: Optimized merging var-keyword arguments and improved error