help needed in subprocess communicate

[rdabane at gmail.com]

I'm trying to perform following type of operation from inside a python
script.
1. Open an application shell (basically a tcl )
2. Run some commands on that shell and get outputs from each command
3. Close the shell


I could do it using communicate if I concatenate all my commands
( separated by newline ) and read all the output in the end. So
basically I could do following sequence:
1. command1 \n command2 \n command 3 \n
2. Read all the output

But I want to perform it interactively.
1. command1
2. read output
3. command2
4. read output ......

Following is my code:

from subprocess import *
p2 = Popen('qdl_tcl',stdin=PIPE,stdout=PIPE)
o,e = p2.communicate(input='qdl_help \n qdl_read /home/rokit/
svnproject/falcon/chip/blocks/intf/bitsif/rtl/m6_bitsif.qdl_cpp \n
qdl_reg_group_list m6_bitsif')


Please suggest a way to perform it interactively with killing the
process each time I want to communicate with it.

Thanks in advance,
-Rahul.