在这里做些学习记录。目标：
1、学会以下概念的基本使用；
2、阅读源码与资料，了解以下概念的实现方式；
3、在12的学习中发现自己还需要补进的知识盲点，加以学习。
Thread
# start a thread
import threading
thread = threading.Thread(target=func, args=(i,))
thread.daemon = True # do some background work
thread.start()
thread.join()
Processing
from multiprocessing import Process
proc = Process(target=func, args=(i,))
proc.start()
proc.join()
Asyncio
async IO is a single-threaded, single-process design: it uses cooperative multitasking. It has been said in other words that async IO gives a feeling of concurrency despite using a single thread in a single process. Coroutines (a central feature of async IO) can be scheduled concurrently, but they are not inherently concurrent.
aysncio runs a single threaded event loop. For blocking events, coroutines will transfer control to ThreadPoolExecutors where functions are executed in a separate thread.
