In contrast to the documentation, os.popen and relatives do not 
support the "U" format character in their constructors.

os.popen("some_nifty_command some_arg", "rU")
throws
OSError: [Errno 22] Invalid argument ,
while os.popen{2,3,4} just ignores "U".
I noticed that behaviour while p-opening oggenc (the ogg vorbis 
encoder), which uses curses for output. The lines end with \r and not 
with \n (due to some ncurses internals, I suspect), so that the file 
objects readline() function cannot split the output.

Logged In: YES 
user_id=45365

Theoretically this is easy to fix: if mode=="U" or "rU" just pass "r" 
to popen(), "rb" to fdopen() and _O_BINARY to the lowlevel calls, 
and the original string to PyFile_FromFile.

But this whole popen{,2,3,4} section of posixmodule.c is so 
fiendishly complicated with all the platform special cases that I'm 
loath to touch it...

Logged In: YES 
user_id=344921

I've added universal newline support to popen5.
http://www.lysator.liu.se/~astrand/popen5/. 

Logged In: YES 
user_id=254205

See
<http://advogato.org/person/follower/diary.html?start=43>
for details of a possible interim work around. (WFM, YMMV)

Logged In: YES 
user_id=254205

See http://advogato.org/person/follower/diary.html?start=43
for details of a possible interim work around. (WFM, YMMV)

Logged In: YES 
user_id=11375

popen5 was added to Python 2.4 as the subprocess module.

It's probably unlikely that someone will go back and fix the
low-level os.popen2() function.  I suggest that this bug be
closed, and we encourage people to use the subprocess module.

Logged In: YES 
user_id=344921

Closing, as suggested by akuchling.