'thread._local'对象没有属性 [英] 'thread._local' object has no attribute

问题描述

我试图通过添加上下文过滤器来更改日志记录格式.我的格式是这样的

I was trying to change the logging format by adding a context filter. My Format is like this

FORMAT = "%(asctime)s %(VAL)s %(message)s"

这是我用来设置VAL格式的类.

This is the class I use to set the VAL in the format.

class TEST:
  def __init__(self, val):
    self.test_var=threading.local()
    self.test_var.value=val
  def filter(self,record):
    record.VAL=self.test_var.value
    return True
  def setValue(self,val)
    self.test_var.value=CMDID

它在单线程环境中可以正常工作，但是对于某些多线程环境，我会收到错误消息

It works fine in a single threaded environment, but for a certain multi-threaded environment I get the error

<Fault 1: "exceptions.AttributeError:'thread._local' object has no attribute 'value'">

有人可以告诉我这是怎么回事吗?以及如何纠正?

Can anyone tell me what's wrong here ?? and how to rectify?

推荐答案

好吧，例外是告诉您，从threading.local()返回的thread._local对象没有可分配val的value属性. >至.您可以通过在self.test_var=threading.local()行之后添加dir(self.test_var)来确认.那对我来说就是这样:

Well, the exception is telling you that the thread._local object returned from threading.local() doesn't have a value attribute that you can assign val to. You can confirm that by adding a dir(self.test_var) after the self.test_var=threading.local() line. That returns this for me:

['__class__', '__delattr__', '__dict__', '__doc__', '__getattribute__', '__hash__',
 '__init__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__',
 '__str__']

实际上，help(threading.local())将向您显示确实存在的方法和属性-value不在其中.

Indeed, help(threading.local()) will show you the methods and attributes that do exist - value is not among them.

如果您尝试添加新属性，那么您可能想要:

If you are attempting to add a new attribute, then perhaps you want:

self.test_var.__setattr__('value',val)

这实际上将创建属性并为其分配值.

This will actually create the attribute and assign the value to it.

通常不简单地通过分配实例属性来创建实例属性，就像非实例变量是...

Instance attributes are not generally created simply by assigning to them, like non-instance variables are...

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