How to achieve interactive subprocess i/o
I'm trying to figure out how to control interactive I/O.
The simplest scenario is like:
Some blackbox script continuously reads a line and writes a line.
Then, it's easy to map input and corresponding output.
blackbox.py:
for i in range(5):
a = input()
print(f'line {i}: {a}')
main.py:
proc = subprocess.Popen(['python3', 'blackbox.py'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
out_str = proc.stdout.readline()
# now I get (in_str, out_str) pair
proc.stdin.close()
proc.terminate()
But what if blackbox.py is like this?:
blackbox.py:
for i in range(5):
a = input()
if some_function(a):
print(f'line {i}: {a}')
elif still_some_function(a):
print(f'foofoo1 {i}: {a}')
print(f'foofoo1 {i}: {a}')
else:
print(f'barbar1 {i}: {a}')
print(f'barbar2 {i}: {a}')
print(f'barbar3 {i}: {a}')
main.py:
# ...
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
# output_str = read_all()
# how can I get (in_str, out_str) pair
# ...
I want read_all() to read the output from proc, which is written between a = input() and next a = input().
Of course stdout.read() will not work since it waits forever until EOF. read_all() waits for EOF or some special signal (if such exists) that the subprocess is again waiting for another input.
As the name suggests, blackbox.py is unknown beforehand. (Assume blackbox.py will never stuck on loop)
python process blocking
edited Nov 24 '18 at 9:52
petezurich
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
add a comment |
I'm trying to figure out how to control interactive I/O.
The simplest scenario is like:
Some blackbox script continuously reads a line and writes a line.
Then, it's easy to map input and corresponding output.
blackbox.py:
for i in range(5):
a = input()
print(f'line {i}: {a}')
main.py:
proc = subprocess.Popen(['python3', 'blackbox.py'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
out_str = proc.stdout.readline()
# now I get (in_str, out_str) pair
proc.stdin.close()
proc.terminate()
But what if blackbox.py is like this?:
blackbox.py:
for i in range(5):
a = input()
if some_function(a):
print(f'line {i}: {a}')
elif still_some_function(a):
print(f'foofoo1 {i}: {a}')
print(f'foofoo1 {i}: {a}')
else:
print(f'barbar1 {i}: {a}')
print(f'barbar2 {i}: {a}')
print(f'barbar3 {i}: {a}')
main.py:
# ...
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
# output_str = read_all()
# how can I get (in_str, out_str) pair
# ...
I want read_all() to read the output from proc, which is written between a = input() and next a = input().
Of course stdout.read() will not work since it waits forever until EOF. read_all() waits for EOF or some special signal (if such exists) that the subprocess is again waiting for another input.
As the name suggests, blackbox.py is unknown beforehand. (Assume blackbox.py will never stuck on loop)
python process blocking
edited Nov 24 '18 at 9:52
petezurich
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
add a comment |
I'm trying to figure out how to control interactive I/O.
The simplest scenario is like:
Some blackbox script continuously reads a line and writes a line.
Then, it's easy to map input and corresponding output.
blackbox.py:
for i in range(5):
a = input()
print(f'line {i}: {a}')
main.py:
proc = subprocess.Popen(['python3', 'blackbox.py'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
out_str = proc.stdout.readline()
# now I get (in_str, out_str) pair
proc.stdin.close()
proc.terminate()
But what if blackbox.py is like this?:
blackbox.py:
for i in range(5):
a = input()
if some_function(a):
print(f'line {i}: {a}')
elif still_some_function(a):
print(f'foofoo1 {i}: {a}')
print(f'foofoo1 {i}: {a}')
else:
print(f'barbar1 {i}: {a}')
print(f'barbar2 {i}: {a}')
print(f'barbar3 {i}: {a}')
main.py:
# ...
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
# output_str = read_all()
# how can I get (in_str, out_str) pair
# ...
I want read_all() to read the output from proc, which is written between a = input() and next a = input().
Of course stdout.read() will not work since it waits forever until EOF. read_all() waits for EOF or some special signal (if such exists) that the subprocess is again waiting for another input.
As the name suggests, blackbox.py is unknown beforehand. (Assume blackbox.py will never stuck on loop)
python process blocking
edited Nov 24 '18 at 9:52
petezurich
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
I'm trying to figure out how to control interactive I/O.
The simplest scenario is like:
Some blackbox script continuously reads a line and writes a line.
Then, it's easy to map input and corresponding output.
blackbox.py:
for i in range(5):
a = input()
print(f'line {i}: {a}')
main.py:
proc = subprocess.Popen(['python3', 'blackbox.py'],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
out_str = proc.stdout.readline()
# now I get (in_str, out_str) pair
proc.stdin.close()
proc.terminate()
But what if blackbox.py is like this?:
blackbox.py:
for i in range(5):
a = input()
if some_function(a):
print(f'line {i}: {a}')
elif still_some_function(a):
print(f'foofoo1 {i}: {a}')
print(f'foofoo1 {i}: {a}')
else:
print(f'barbar1 {i}: {a}')
print(f'barbar2 {i}: {a}')
print(f'barbar3 {i}: {a}')
main.py:
# ...
for text in ['Mon', 'Tue', 'Wed', 'Thu', 'Fri']:
in_str = bytes(f'{text}n')
proc.stdin.write(in_str, 'utf-8'))
proc.stdin.flush()
# output_str = read_all()
# how can I get (in_str, out_str) pair
# ...
I want read_all() to read the output from proc, which is written between a = input() and next a = input().
Of course stdout.read() will not work since it waits forever until EOF. read_all() waits for EOF or some special signal (if such exists) that the subprocess is again waiting for another input.
As the name suggests, blackbox.py is unknown beforehand. (Assume blackbox.py will never stuck on loop)
python process blocking
python process blocking
edited Nov 24 '18 at 9:52
petezurich
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
edited Nov 24 '18 at 9:52
petezurich
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
edited Nov 24 '18 at 9:52
petezurich
3,65081834
edited Nov 24 '18 at 9:52
petezurich
3,65081834
edited Nov 24 '18 at 9:52
petezurich
3,65081834
3,65081834
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
asked Nov 24 '18 at 8:29
theGivingTreetheGivingTree
5319
5319
add a comment |
add a comment |
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