bpo-43787: Add __iter__ to GzipFile, BZ2File, and LZMAFile (GH-25353)

4 files changed, 15 insertions, 0 deletions

diff --git a/Lib/bz2.py b/Lib/bz2.py
index 43f321a..a2c588e 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -197,6 +197,10 @@ class BZ2File(_compression.BaseStream):
         self._check_can_read()
         return self._buffer.readline(size)
 
+    def __iter__(self):
+        self._check_can_read()
+        return self._buffer.__iter__()
+
     def readlines(self, size=-1):
         """Read a list of lines of uncompressed bytes from the file.
 
diff --git a/Lib/gzip.py b/Lib/gzip.py
index 0a8993b..9a4e0f9 100644
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -398,6 +398,10 @@ class GzipFile(_compression.BaseStream):
         self._check_not_closed()
         return self._buffer.readline(size)
 
+    def __iter__(self):
+        self._check_not_closed()
+        return self._buffer.__iter__()
+
 
 class _GzipReader(_compression.DecompressReader):
     def __init__(self, fp):
diff --git a/Lib/lzma.py b/Lib/lzma.py
index c8b1970..2ada7d8 100644
--- a/Lib/lzma.py
+++ b/Lib/lzma.py
@@ -221,6 +221,10 @@ class LZMAFile(_compression.BaseStream):
         self._check_can_read()
         return self._buffer.readline(size)
 
+    def __iter__(self):
+        self._check_can_read()
+        return self._buffer.__iter__()
+
     def write(self, data):
         """Write a bytes object to the file.
 
diff --git a/Misc/NEWS.d/next/Library/2021-04-12-15-15-50.bpo-43787.wCy_Wd.rst b/Misc/NEWS.d/next/Library/2021-04-12-15-15-50.bpo-43787.wCy_Wd.rst
new file mode 100644
index 0000000..9b8d945
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-04-12-15-15-50.bpo-43787.wCy_Wd.rst
@@ -0,0 +1,3 @@
+Add ``__iter__()`` method to :class:`bz2.BZ2File`, :class:`gzip.GzipFile`, and
+:class:`lzma.LZMAFile`. It makes iterating them about 2x faster. Patch by
+Inada Naoki.