Python多线程下的_strptime问题
由于Python的datetime和time中的_strptime方法不支持多线程，运行时会报错：
import datetime
import thread
import time
def f():
datetime.datetime.strptime("20100101","%Y%m%d")
for _ in xrange(3):
thread.start_new_thread(f, ())
time.sleep(3)
Unhandled exception in thread started by <function f at 0x2b52c24e66e0>
Traceback (most recent call last):
File "test.py", line 7, in f
datetime.datetime.strptime("20100101","%Y%m%d")
AttributeErrorUnhandled exception in thread started by <function f at 0x2b52c24e66e0>:
Traceback (most recent call last):
File "test.py", line 7, in f
_strptime
datetime.datetime.strptime("20100101","%Y%m%d")
AttributeError: _strptime
参考 http://bugs.python.org/issue7980
在源文件中可以fix这个bug，不过对于用户来说，还是在使用的时候加锁吧。。
c = threading.RLock()
def f():
with c:
datetime.datetime.strptime("20100101","%Y%m%d")
RLock参考
