在 Python 中检查当前线程是否为主线程
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/23206787/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Check if current thread is main thread, in Python
提问by jonny
This has been answered for Android, Objective Cand C++before, but apparently not for Python. How do I reliably determine whether the current thread is the main thread? I can think of a few approaches, none of which really satisfy me, considering it could be as easy as comparing to threading.MainThreadif it existed.
之前已经针对Android、Objective C和C++回答了这个问题，但显然没有针对 Python回答。如何可靠地确定当前线程是否为主线程？我能想到一些方法，但没有一个真正让我满意，因为它可以像比较threading.MainThread它是否存在一样简单。
Check the thread name
检查线程名称
The main thread is instantiated in threading.pylike this:
主线程实例化threading.py如下：
Thread.__init__(self, name="MainThread")
so one could do
所以可以做
if threading.current_thread().name == 'MainThread'
but is this name fixed? Other codes I have seen checked whether MainThreadis contained anywhere in the thread's name.
但是这个名字是固定的吗？我见过的其他代码检查是否MainThread包含在线程名称中的任何位置。
Store the starting thread
存储起始线程
I could store a reference to the starting thread the moment the program starts up, i.e. while there are no other threads yet. This would be absolutely reliable, but way too cumbersome for such a simple query?
我可以在程序启动时存储对起始线程的引用，即当还没有其他线程时。这绝对可靠，但对于这样一个简单的查询来说太麻烦了？
Is there a more concise way of doing this?
有没有更简洁的方法来做到这一点？
采纳答案by s16h
The problem with threading.current_thread().name == 'MainThread'is that one can always do:
问题threading.current_thread().name == 'MainThread'在于，人们总是可以做到：
threading.current_thread().name = 'MyName'
assert threading.current_thread().name == 'MainThread' # will fail
Perhaps the following is more solid:
也许以下内容更可靠：
threading.current_thread().__class__.__name__ == '_MainThread'
Having said that, one may still cunningly do:
话虽如此，人们可能仍然狡猾地这样做：
threading.current_thread().__class__.__name__ = 'Grrrr'
assert threading.current_thread().__class__.__name__ == '_MainThread' # will fail
But this option still seems better; "after all, we're all consenting adults here."
但是这个选项似乎仍然更好；“毕竟，我们这里都是成年人。”
UPDATE:
更新：
Python 3.4 introduced threading.main_thread()which is much better than the above:
引入的 Python 3.4threading.main_thread()比上面的要好得多：
assert threading.current_thread() is threading.main_thread()
UPDATE 2:
更新 2：
For Python < 3.4, perhaps the best option is:
对于 Python < 3.4，也许最好的选择是：
isinstance(threading.current_thread(), threading._MainThread)
回答by asherbar
If, like me, accessing protected attributes gives you the Heebie-jeebies, you may want an alternative for using threading._MainThread, as suggested. In that case, you may exploit the fact that only the Main Thread can handle signals, so the following can do the job:
如果像我一样，访问受保护的属性会给您带来 Heebie-jeebies，那么您可能需要使用 的替代方法threading._MainThread，如建议的。在这种情况下，您可以利用只有主线程可以处理信号的事实，因此以下可以完成这项工作：
import signal
def is_main_thread():
try:
# Backup the current signal handler
back_up = signal.signal(signal.SIGINT, signal.SIG_DFL)
except ValueError:
# Only Main Thread can handle signals
return False
# Restore signal handler
signal.signal(signal.SIGINT, back_up)
return True
Updated to address potential issue as pointed out by @user4815162342.
更新以解决@user4815162342 指出的潜在问题。
回答by wim
The answers here are old and/or bad, so here's a current solution:
这里的答案是旧的和/或不好的，所以这是一个当前的解决方案：
if threading.current_thread() is threading.main_thread():
...
This method is available since Python 3.4+.
此方法自 Python 3.4+ 起可用。
