Dialog with a process via subprocess.Popen blocks forever

[bayer.justin at googlemail.com]

Hi,

I am trying to communicate with a subprocess via the subprocess
module. Consider the following example:

>>> from subprocess import Popen, PIPE
>>> Popen("""python -c 'input("hey")'""", shell=True)
<subprocess.Popen object at 0x729f0>
>>> hey

Here hey is immediately print to stdout of my interpreter, I did not
type in the "hey". But I want to read from the output into a string,
so I do

>>> x = Popen("""python -c 'input("hey\n")'""", shell=True, stdout=PIPE, bufsize=2**10)
>>> x.stdout.read(1)
# blocks forever

Is it possible to read to and write to the std streams of a
subprocess? What am I doing wrong?

Regards,
-Justin