asyncio-bash

#!/usr/bin/env python3

import asyncio
import sys

class StdOutProtocol(asyncio.SubprocessProtocol):
    def __init__(self, exit_future):
        self.exit_future = exit_future
        self.output = bytearray()
    def pipe_data_received(self, fd, data):
        self.output.extend(data)
    def process_exited(self):
        self.exit_future.set_result(True)

@asyncio.coroutine
def run_sh(loop, sh_command):
    exit_future = asyncio.Future(loop=loop)

    # Create the subprocess controlled by the protocol StdOutProtocol, redirect the standard output into a pipe
    transport, protocol = yield from loop.subprocess_exec(lambda: StdOutProtocol(exit_future),
                                                          'sh', '-c' , sh_command,
                                                          stdin=None, stderr=None)

    # Wait for the subprocess exit using the process_exited() method of the protocol
    yield from exit_future

    # Close the stdout pipe
    transport.close()

    # Read the output which was collected by the pipe_data_received() method of the protocol
    data = bytes(protocol.output)
    return data.decode('ascii').rstrip()

loop = asyncio.get_event_loop()
result = loop.run_until_complete(run_sh(loop, 'sleep 2 && date +%Y-%m-%d'))
print("result:", result)
loop.close()