Issue #19223: Add support for the 'x' mode to the bz2 module.

Patch by Tim Heaney and Vajrasky Kok.

1 files changed, 10 insertions, 6 deletions

diff --git a/Lib/bz2.py b/Lib/bz2.py
index 6e6a2b9..6bc611e 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -49,12 +49,12 @@ class BZ2File(io.BufferedIOBase):
         which will be used to read or write the compressed data.
 
         mode can be 'r' for reading (default), 'w' for (over)writing,
-        or 'a' for appending. These can equivalently be given as 'rb',
-        'wb', and 'ab'.
+        'x' for creating exclusively, or 'a' for appending. These can
+        equivalently be given as 'rb', 'wb', 'xb', and 'ab'.
 
         buffering is ignored. Its use is deprecated.
 
-        If mode is 'w' or 'a', compresslevel can be a number between 1
+        If mode is 'w', 'x' or 'a', compresslevel can be a number between 1
         and 9 specifying the level of compression: 1 produces the least
         compression, and 9 (default) produces the most compression.
 
@@ -87,6 +87,10 @@ class BZ2File(io.BufferedIOBase):
             mode = "wb"
             mode_code = _MODE_WRITE
             self._compressor = BZ2Compressor(compresslevel)
+        elif mode in ("x", "xb"):
+            mode = "xb"
+            mode_code = _MODE_WRITE
+            self._compressor = BZ2Compressor(compresslevel)
         elif mode in ("a", "ab"):
             mode = "ab"
             mode_code = _MODE_WRITE
@@ -443,9 +447,9 @@ def open(filename, mode="rb", compresslevel=9,
     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 mode argument can be "r", "rb", "w", "wb", "a" or "ab" for
-    binary mode, or "rt", "wt" or "at" for text mode. The default mode
-    is "rb", and the default compresslevel is 9.
+    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.
+    The default mode is "rb", and the default compresslevel is 9.
 
     For binary mode, this function is equivalent to the BZ2File
     constructor: BZ2File(filename, mode, compresslevel). In this case,