常见的multiprocessing, threading, multiprocessing.dummy
这些多进程，多线程，都是没有返回结果
multiprocessing
from multiprocessing import Process, Pool
def p():
print("p")
p1 = Process(target=p,)
p1.start()
p1.join()
#进程池
p5 = Pool(processes=3)
p5.apply_async(p)
p5.close()
threading
from threading import Thread
p2 = Thread(target=p,)
p2.start()
p2.join()
multiprocessing.dummy
from multiprocessing.dummy import Pool as ThreadPool
def md():
pool = ThreadPool(3)
# 在各个线程中打开url，并返回结果
results = pool.map(p,[])
# 关闭线程池，等待工作结束
pool.close()
pool.join()
md()
concurrent.futures带返回结果
多线程，多进程带返回结果
from concurrent.futures import ThreadPoolExecutor, ProcessPoolExecutor
def p():
return "p"
with ThreadPoolExecutor(max_workers=2) as executor:
r = executor.submit(p)
print(r.result())
如何concurrent.futures扩展写一个多线程装饰器
示例
from tomorrow import threads
@threads(5)
def p():
return "p"
t = p()
print(t._future._result)
tomorrow源码
rom functools import wraps
from concurrent.futures import ThreadPoolExecutor
class Tomorrow():
def __init__(self, future, timeout):
self._future = future
self._timeout = timeout
def __getattr__(self, name):
result = self._wait()
return result.__getattribute__(name)
def _wait(self):
return self._future.result(self._timeout)
def async(n, base_type, timeout=None):
def decorator(f):
if isinstance(n, int):
pool = base_type(n)
elif isinstance(n, base_type):
pool = n
else:
raise TypeError(
"Invalid type: %s"
% type(base_type)
)
@wraps(f)
def wrapped(*args, **kwargs):
return Tomorrow(
pool.submit(f, *args, **kwargs), # 创建future对象
timeout=timeout
)
return wrapped
return decorator
def threads(n, timeout=None):
return async(n, ThreadPoolExecutor, timeout)
