asyncio-stdin-commands.py

import asyncio
import sys
import time
import re

cmd_regexp = re.compile('^([a-zA-Z0-9_-]+?)(\\((.*)\\))?$')
async def read_command(loop):
    line = await loop.run_in_executor(None, sys.stdin.readline)
    line = line.rstrip()  # remove new line
    cmd = None
    params = None
    match = cmd_regexp.match(line)
    if match:
        cmd = match[1]
        params = (match[3] or '').split(',')
        params = list(filter(None, params))
        params = list(map(lambda x: x.strip(), params))
    return (cmd, params)

def do_some_work(seconds):
    time.sleep(seconds)
    return f'{seconds} seconds'

async def main_loop():
    command_future = asyncio.ensure_future(read_command(loop))
    for i in range(10):
        res = await loop.run_in_executor(None, do_some_work, 3)
        print(f'exec {res}')
        if command_future.done():
            (cmd, params) = command_future.result()
            print(f'received {cmd} {params}')
            if (cmd == 'exit'):
                break
            command_future = asyncio.ensure_future(read_command(loop))
    if not command_future.done():
        print('press ENTER to finish')
        await command_future
    loop.stop()

loop = asyncio.get_event_loop()
asyncio.ensure_future(main_loop())
loop.run_forever()
loop.close()
print('done')