gh-87901: Add encoding to os.popen (GH-92374)

Author: methane

Doc/library/os.rst

@@ -3916,12 +3916,13 @@ written in Python, such as a mail server's external command delivery program.
    .. availability:: Unix.
 
 
-.. function:: popen(cmd, mode='r', buffering=-1)
+.. function:: popen(cmd, mode='r', buffering=-1, encoding=None)
 
    Open a pipe to or from command *cmd*.
    The return value is an open file object
    connected to the pipe, which can be read or written depending on whether *mode*
-   is ``'r'`` (default) or ``'w'``. The *buffering* argument has the same meaning as
+   is ``'r'`` (default) or ``'w'``.
+   The *buffering* and *encoding* arguments have the same meaning as
    the corresponding argument to the built-in :func:`open` function. The
    returned file object reads or writes text strings rather than bytes.
 
@@ -3944,6 +3945,9 @@ written in Python, such as a mail server's external command delivery program.
    documentation for more powerful ways to manage and communicate with
    subprocesses.
 
+   .. versionchanged:: 3.11
+      Added the *encoding* parameter.
+
 
 .. function:: posix_spawn(path, argv, env, *, file_actions=None, \
                           setpgroup=None, resetids=False, setsid=False, setsigmask=(), \

Lib/os.py

@@ -974,14 +974,15 @@ def spawnlpe(mode, file, *args):
 # command in a shell can't be supported.
 if sys.platform != 'vxworks':
     # Supply os.popen()
-    def popen(cmd, mode="r", buffering=-1):
+    def popen(cmd, mode="r", buffering=-1, encoding=None):
         if not isinstance(cmd, str):
             raise TypeError("invalid cmd type (%s, expected string)" % type(cmd))
         if mode not in ("r", "w"):
             raise ValueError("invalid mode %r" % mode)
         if buffering == 0 or buffering is None:
             raise ValueError("popen() does not support unbuffered streams")
         import subprocess, io
+        encoding = io.text_encoding(encoding)
         if mode == "r":
             proc = subprocess.Popen(cmd,
                                     shell=True, text=True,

Misc/NEWS.d/next/Library/2022-05-06-13-53-10.gh-issue-87901.NnkUVr.rst

@@ -0,0 +1 @@
+Add the *encoding* parameter to :func:`os.popen`.