add python_thread_multiprocess.py

master
xianhu 2016-12-09 19:40:26 +08:00
parent 7ced2be8fe
commit c3977819d8
2 changed files with 117 additions and 0 deletions

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### python_coroutine.py: Python进阶: 理解Python中的异步IO和协程(Coroutine), 并应用在爬虫中
### python_aiohttp.py: Python中最好用的异步爬虫库Aiohttp代码实例
### python_thread_multiprocess.py: Python进阶: 聊聊IO密集型任务、计算密集型任务以及多线程、多进程
===================================================================================================
### 您可以fork该项目,并在修改后提交Pull request

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# _*_ coding: utf-8 _*_
"""
python_thread_multiprocee.py by xianhu
"""
import time
import threading
import multiprocessing
# 定义全局变量Queue
g_queue = multiprocessing.Queue()
g_search_list = list(range(10000))
# 定义一个IO密集型任务利用time.sleep()
def task_io(task_id):
print("IOTask[%s] start" % task_id)
while not g_queue.empty():
time.sleep(1)
try:
data = g_queue.get(block=True, timeout=1)
print("IOTask[%s] get data: %s" % (task_id, data))
except Exception as excep:
print("IOTask[%s] error: %s" % (task_id, str(excep)))
print("IOTask[%s] end" % task_id)
return
# 定义一个计算密集型任务:利用一些复杂加减乘除、列表查找等
def task_cpu(task_id):
print("CPUTask[%s] start" % task_id)
while not g_queue.empty():
count = 0
for i in range(10000):
count += pow(3*2, 3*2) if i in g_search_list else 0
try:
data = g_queue.get(block=True, timeout=1)
print("CPUTask[%s] get data: %s" % (task_id, data))
except Exception as excep:
print("CPUTask[%s] error: %s" % (task_id, str(excep)))
print("CPUTask[%s] end" % task_id)
return task_id
def init_queue():
print("init g_queue start")
while not g_queue.empty():
g_queue.get()
for _index in range(10):
g_queue.put(_index)
print("init g_queue end")
return
if __name__ == '__main__':
print("cpu count:", multiprocessing.cpu_count(), "\n")
print("========== 直接执行IO密集型任务 ==========")
init_queue()
time_0 = time.time()
task_io(0)
print("结束:", time.time() - time_0, "\n")
print("========== 多线程执行IO密集型任务 ==========")
init_queue()
time_0 = time.time()
thread_list = [threading.Thread(target=task_io, args=(i,)) for i in range(5)]
for t in thread_list:
t.start()
for t in thread_list:
if t.is_alive():
t.join()
print("结束:", time.time() - time_0, "\n")
print("========== 多进程执行IO密集型任务 ==========")
init_queue()
time_0 = time.time()
process_list = [multiprocessing.Process(target=task_io, args=(i,)) for i in range(multiprocessing.cpu_count())]
for p in process_list:
p.start()
for p in process_list:
if p.is_alive():
p.join()
print("结束:", time.time() - time_0, "\n")
print("========== 直接执行CPU密集型任务 ==========")
init_queue()
time_0 = time.time()
task_cpu(0)
print("结束:", time.time() - time_0, "\n")
print("========== 多线程执行CPU密集型任务 ==========")
init_queue()
time_0 = time.time()
thread_list = [threading.Thread(target=task_cpu, args=(i,)) for i in range(5)]
for t in thread_list:
t.start()
for t in thread_list:
if t.is_alive():
t.join()
print("结束:", time.time() - time_0, "\n")
print("========== 多进程执行cpu密集型任务 ==========")
init_queue()
time_0 = time.time()
process_list = [multiprocessing.Process(target=task_cpu, args=(i,)) for i in range(multiprocessing.cpu_count())]
for p in process_list:
p.start()
for p in process_list:
if p.is_alive():
p.join()
print("结束:", time.time() - time_0, "\n")
exit()