如何在Python中找到线程ID

问题:如何在Python中找到线程ID

我有一个多线程Python程序和一个实用程序函数, writeLog(message),该写出时间戳记和消息。不幸的是,结果日志文件没有给出哪个线程正在生成哪个消息的指示。

我希望writeLog()能够在消息中添加一些内容,以标识哪个线程正在调用它。显然,我可以使线程将这些信息传递进来,但这将需要更多工作。是否有一些os.getpid()我可以使用的等效线程?

I have a multi-threading Python program, and a utility function, writeLog(message), that writes out a timestamp followed by the message. Unfortunately, the resultant log file gives no indication of which thread is generating which message.

I would like writeLog() to be able to add something to the message to identify which thread is calling it. Obviously I could just make the threads pass this information in, but that would be a lot more work. Is there some thread equivalent of os.getpid() that I could use?


回答 0

threading.get_ident(),或threading.current_thread().ident(或(threading.currentThread().ident对于python <2.6)。

threading.get_ident() works, or threading.current_thread().ident (or threading.currentThread().ident for Python < 2.6).


回答 1

使用日志记录模块,您可以在每个日志条目中自动添加当前线程标识符。只需在记录器格式字符串中使用以下LogRecord映射键之一:

%(thread)d: 线程ID(如果有)。

%(threadName)s: 线程名称(如果有)。

并使用它设置默认处理程序:

logging.basicConfig(format="%(threadName)s:%(message)s")

Using the logging module you can automatically add the current thread identifier in each log entry. Just use one of these LogRecord mapping keys in your logger format string:

%(thread)d : Thread ID (if available).

%(threadName)s : Thread name (if available).

and set up your default handler with it:

logging.basicConfig(format="%(threadName)s:%(message)s")

回答 2

thread.get_ident()函数在Linux上返回一个长整数。这实际上不是线程ID。

我使用这种方法来真正获取Linux上的线程ID:

import ctypes
libc = ctypes.cdll.LoadLibrary('libc.so.6')

# System dependent, see e.g. /usr/include/x86_64-linux-gnu/asm/unistd_64.h
SYS_gettid = 186

def getThreadId():
   """Returns OS thread id - Specific to Linux"""
   return libc.syscall(SYS_gettid)

The thread.get_ident() function returns a long integer on Linux. It’s not really a thread id.

I use this method to really get the thread id on Linux:

import ctypes
libc = ctypes.cdll.LoadLibrary('libc.so.6')

# System dependent, see e.g. /usr/include/x86_64-linux-gnu/asm/unistd_64.h
SYS_gettid = 186

def getThreadId():
   """Returns OS thread id - Specific to Linux"""
   return libc.syscall(SYS_gettid)

回答 3


回答 4

我看到了这样的线程ID的示例:

class myThread(threading.Thread):
    def __init__(self, threadID, name, counter):
        self.threadID = threadID
        ...

线程模块文档列表name属性,以及:

...

A thread has a name. 
The name can be passed to the constructor, 
and read or changed through the name attribute.

...

Thread.name

A string used for identification purposes only. 
It has no semantics. Multiple threads may
be given the same name. The initial name is set by the constructor.

I saw examples of thread IDs like this:

class myThread(threading.Thread):
    def __init__(self, threadID, name, counter):
        self.threadID = threadID
        ...

The threading module docs lists name attribute as well:

...

A thread has a name. 
The name can be passed to the constructor, 
and read or changed through the name attribute.

...

Thread.name

A string used for identification purposes only. 
It has no semantics. Multiple threads may
be given the same name. The initial name is set by the constructor.

回答 5

您可以获得当前正在运行的线程的标识。如果当前线程结束,则该标识可以重用于其他线程。

创建线程实例时,将为该线程隐式指定一个名称,即模式:线程号

名称没有意义,名称不必唯一。所有正在运行的线程的标识都是唯一的。

import threading


def worker():
    print(threading.current_thread().name)
    print(threading.get_ident())


threading.Thread(target=worker).start()
threading.Thread(target=worker, name='foo').start()

函数threading.current_thread()返回当前正在运行的线程。该对象保存线程的全部信息。

You can get the ident of the current running thread. The ident could be reused for other threads, if the current thread ends.

When you crate an instance of Thread, a name is given implicit to the thread, which is the pattern: Thread-number

The name has no meaning and the name don’t have to be unique. The ident of all running threads is unique.

import threading


def worker():
    print(threading.current_thread().name)
    print(threading.get_ident())


threading.Thread(target=worker).start()
threading.Thread(target=worker, name='foo').start()

The function threading.current_thread() returns the current running thread. This object holds the whole information of the thread.


回答 6

我在Python中创建了多个线程,打印了线程对象,并使用ident变量打印了id 。我看到所有ID都一样:

<Thread(Thread-1, stopped 140500807628544)>
<Thread(Thread-2, started 140500807628544)>
<Thread(Thread-3, started 140500807628544)>

I created multiple threads in Python, I printed the thread objects, and I printed the id using the ident variable. I see all the ids are same:

<Thread(Thread-1, stopped 140500807628544)>
<Thread(Thread-2, started 140500807628544)>
<Thread(Thread-3, started 140500807628544)>

回答 7

与@brucexin类似,我需要获取操作系统级别的线程标识符(!= thread.get_ident()),并使用如下所示的内容来不依赖于特定的数字并且仅使用amd64:

---- 8< ---- (xos.pyx)
"""module xos complements standard module os""" 

cdef extern from "<sys/syscall.h>":                                                             
    long syscall(long number, ...)                                                              
    const int SYS_gettid                                                                        

# gettid returns current OS thread identifier.                                                  
def gettid():                                                                                   
    return syscall(SYS_gettid)                                                                  

---- 8< ---- (test.py)
import pyximport; pyximport.install()
import xos

...

print 'my tid: %d' % xos.gettid()

这取决于Cython。

Similarly to @brucexin I needed to get OS-level thread identifier (which != thread.get_ident()) and use something like below not to depend on particular numbers and being amd64-only:

---- 8< ---- (xos.pyx)
"""module xos complements standard module os""" 

cdef extern from "<sys/syscall.h>":                                                             
    long syscall(long number, ...)                                                              
    const int SYS_gettid                                                                        

# gettid returns current OS thread identifier.                                                  
def gettid():                                                                                   
    return syscall(SYS_gettid)                                                                  

and

---- 8< ---- (test.py)
import pyximport; pyximport.install()
import xos

...

print 'my tid: %d' % xos.gettid()

this depends on Cython though.