I've got an interactive program called my_own_exe. First, it prints out alive, then you input S\n and then it prints out alive again. Finally you input L\n. It does some processing and exits.

However, when I call it from the following python script, the program seemed to hang after printing out the first 'alive'.

Can anyone here tell me why this is happening?

// after reading the follow ups (thank you guys), i modified the code as following:

import subprocess
import time

base_command = "./AO_FelixStrategy_UnitTest --bats 31441 --chix 12467 --enxutp 31884 --turq 26372 --symbol SOGN --target_date " + '2009-Oct-16'
print base_command

proc2 = subprocess.Popen(base_command, shell=True , stdin=subprocess.PIPE,)

time.sleep(2);
print "aliv"
proc2.communicate('S\n')

print "alive"
time.sleep(6)

print "alive"
print proc2.communicate('L\n')
time.sleep(6)

the program now goes well with the first input 'S\n', but then stopped, and I the second 'L\n' is kinda ignored.

Can anyone give me an idea why it's like this?

python subprocess
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