大约有 48,000 项符合查询结果（耗时：0.0341秒） [XML]
How do I correctly clean up a Python object?
__del__(self) above fails with an AttributeError exception. I understand Python doesn't guarantee the existence of "global variables" (member data in this context?) when __del__() is invoked. If that is the case and this is the reason for the exception, how do I make sure the object destructs...
How does @synchronized lock/unlock in Objective-C?
Does @synchronized not use "lock" and "unlock" to achieve mutual exclusion? How does it do lock/unlock then?
5 Answers
...
How do I add a path to PYTHONPATH in virtualenv
... you can also navigate to your virtual environment's site-packages folder and create a symbolic link to the .pth file like this: ln -s path/to/somfile.pth. I found this useful when I needed the same directory to be accessible in multiple virtual environments
– Data-phile
...
Is gettimeofday() guaranteed to be of microsecond resolution?
...h, I believe the resolution of gettimeofday() is 10us. It can jump forward and backward and time, consequently, based on the processes running on your system. This effectively makes the answer to your question no.
You should look into clock_gettime(CLOCK_MONOTONIC) for timing intervals. It suffers ...
Why isn't sizeof for a struct equal to the sum of sizeof of each member?
...y alignment constraints. Data structure alignment impacts both performance and correctness of programs:
Mis-aligned access might be a hard error (often SIGBUS).
Mis-aligned access might be a soft error.
Either corrected in hardware, for a modest performance-degradation.
Or corrected by emulation...
Python Requests and persistent sessions
...n 2.5).
I have figured out how to submit data to a login form on a website and retrieve the session key, but I can't see an obvious way to use this session key in subsequent requests.
Can someone fill in the ellipsis in the code below or suggest another approach?
...
How to produce a range with step n in bash? (generate a sequence of numbers with increments)
...rd a guess that the downvote was due to your answer being generic to 'sh', and not specific to 'bash'. The pure Bash approach {begin end step} performs just a little better.The older 'seq' method's handy on older or smaller-memory systems like busybox. I did upvote both your and TheBonsai's answ...
oracle:完整剖析PL/SQL DEVELOPER与SQL PLUS字符集设置 - 数据库(内核) - ...
...hen selected, Unicode data will be fetched as such from the Oracle Server, and displayed as Unicode text. When disabled, Unicode data from the server will be converted to the character set of the Oracle Client, in accordance with the NLS_LANG key of the Oracle Home Registry. -----------from pl/sql...
How do I get a Cron like scheduler in Python? [closed]
I'm looking for a library in Python which will provide at and cron like functionality.
9 Answers
...
Vagrant reverse port forwarding?
...
When you run vagrant ssh, it's actually using this underlying command:
ssh -p 2222 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o LogLevel=ERROR -o IdentitiesOnly=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you ...