Python多線程下存在_strptime的問題

由於Python的datetime和time中的_strptime方法不支持多線程，運行時會報錯：AttributeError: _strptime

code:

# -*- coding:utf-8 -*-
import threading
import time
import datetime


ISO8601_INT_SECONDS = '%Y-%m-%dT%H:%M:%SZ'
expiry_string = "2018-01-04T04:23:02Z"


def test_thread(expiry_string):
    expiry = datetime.datetime.strptime(
                    expiry_string, ISO8601_INT_SECONDS)
    print expiry


threads = []
for i in xrange(5):
    t = threading.Thread(target=test_thread, args=(expiry_string,))
    threads.append(t)

for t in threads:
    t.start()

for t in threads:
    t.join()

print "every thing is ok!!!"

會報錯誤：AttributeError: 'module' object has no attribute '_strptime'

 

解決方案：

1.在調用_strptime的地方加鎖(推薦)

方式1.

c = threading.RLock()
def f():
    with c:
        datetime.datetime.strptime("20100101","%Y%m%d")

方式2：

LOCK = thread.allocate_lock()

 LOCK.acquire()

 datetime.datetime.strptime("20100101","%Y%m%d")

 LOCK.release()

 

2、在線程啟動前調用一次_strptime（原因是報了這個錯），不是很推薦

方式1、import _strptime

方式2、在調用線程前執行一次： datetime.datetime.strptime("20100101","%Y%m%d")。(似乎對我們不合適)

 

參考資料：

http://www.cnblogs.com/dkblog/archive/2012/12/31/2840536.html  

https://bugs.python.org/issue7980 

https://stackoverflow.com/questions/32245560/module-object-has-no-attribute-strptime-with-several-threads-python 

https://stackoverflow.com/questions/2427240/thread-safe-equivalent-to-pythons-time-strptime