Concurrent Execution

多进程multiprocessing
- Pool
  - imap_unordered
- ThreadPool

线程 Threading 

Thread

new_thread = threading.Thread(target=<function>, args=[], kwargs={})
new_thread.start()
new_thread.join()
new_thread.run()  # run的话就不起线程了，和直接调用f是一个效果

如果线程报错了, 不会影响后续执行, 想要抓住这个exception, 就用ThreadPool吧

from threading import Thread
s1 = Thread(None, function, args=[], kwargs={})
s2 = Thread(None, function2, args=[], kwargs={})
s1.start()
s2.start()

threading.get_native_id() 获取当前线程的id
Thread-Local Data:
使用treading.local()可以获取本线程的变量。这个变量在几个线程内不相通
测试2个thread的变量
Lock 线程锁, 一个线程只能拿到一个
RLock 线程锁. 同一个线程内可以多次获取

multiprocessing — Process-based parallelism 

Process

如果不join,直接关闭直到主进程都要退出的时候，会等待子进程的结束

获取进程数据

[ ] concurrent.futures

[subprocess][subprocess]

基础用法

import subprocess
try:
    res = subprocess.run(["ls", "-l"], capture_output=True, check=True)
    print(res.stdout.decode("utf-8"))
except subprocess.TimeoutExpired as e:
    logger.exception(e)
    logger.exception("超时了")
except subprocess.CalledProcessError as e:
    logger.exception(e)
    logger.error(f"执行任务失败")

输入输出测试代码

proc = subprocess.Popen(["sh", "input.sh"], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
outs, errs = proc.communicate(
    input="1\n2\nexit\n".encode("utf-8"), timeout=1)
print(outs.decode('utf-8'))

异步执行 Popen

from subprocess import Popen
thread = Popen(["python", "-m", "pyftpdlib"])
time.sleep(10)
thread.kill()

[ ] sched