EasyProcess is an easy to use python subprocess interface.
Links:
Features:
- layer on top of subprocess module
- easy to start, stop programs
- easy to get standard output/error, return code of programs
- command can be list (preferred) or string (command string is converted to list using shlex.split)
- logging
- timeout
- shell is not supported
- pipes are not supported
- stdout/stderr is set only after the subprocess has finished
- stop() does not kill whole subprocess tree
- unicode support
- supported python versions: 3.7, 3.8, 3.9, 3.10
- Method chaining
Installation:
$ python3 -m pip install EasyProcess
Examples:
# easyprocess/examples/hello.py
from easyprocess import EasyProcess
cmd = ["echo", "hello"]
s = EasyProcess(cmd).call().stdout
print(s)
Output:
$ python3 -m easyprocess.examples.hello
hello
# easyprocess/examples/cmd.py
import sys
from easyprocess import EasyProcess
python = sys.executable
print("-- Run program, wait for it to complete, get stdout:")
s = EasyProcess([python, "-c", "print(3)"]).call().stdout
print(s)
print("-- Run program, wait for it to complete, get stderr:")
s = EasyProcess([python, "-c", "import sys;sys.stderr.write('4\\n')"]).call().stderr
print(s)
print("-- Run program, wait for it to complete, get return code:")
s = EasyProcess([python, "--version"]).call().return_code
print(s)
print("-- Run program, wait 1.5 second, stop it, get stdout:")
prog = """
import time
for i in range(10):
print(i, flush=True)
time.sleep(1)
"""
s = EasyProcess([python, "-c", prog]).start().sleep(1.5).stop().stdout
print(s)
Output:
$ python3 -m easyprocess.examples.cmd
-- Run program, wait for it to complete, get stdout:
3
-- Run program, wait for it to complete, get stderr:
4
-- Run program, wait for it to complete, get return code:
0
-- Run program, wait 1.5 second, stop it, get stdout:
0
1
Shell commands are not supported.
echo
is a shell command on Windows (there is no echo.exe),
but it is a program on Linux.
EasyProcess.return_code
is None until
EasyProcess.stop
or EasyProcess.wait
is called.
By using with
statement the process is started
and stopped automatically:
from easyprocess import EasyProcess
with EasyProcess('ping 127.0.0.1') as proc: # start()
# communicate with proc
pass
# stopped
Equivalent with:
from easyprocess import EasyProcess
proc = EasyProcess('ping 127.0.0.1').start()
try:
# communicate with proc
pass
finally:
proc.stop()
This was implemented with "daemon thread".
"The entire Python program exits when only daemon threads are left." https://docs.python.org/library/threading.html
# easyprocess/examples/timeout.py
import sys
from easyprocess import EasyProcess
python = sys.executable
prog = """
import time
for i in range(3):
print(i, flush=True)
time.sleep(1)
"""
print("-- no timeout")
stdout = EasyProcess([python, "-c", prog]).call().stdout
print(stdout)
print("-- timeout=1.5s")
stdout = EasyProcess([python, "-c", prog]).call(timeout=1.5).stdout
print(stdout)
print("-- timeout=50s")
stdout = EasyProcess([python, "-c", prog]).call(timeout=50).stdout
print(stdout)
Output:
$ python3 -m easyprocess.examples.timeout
-- no timeout
0
1
2
-- timeout=1.5s
0
1
-- timeout=50s
0
1
2