__del__ and logging

[flupke]

Hi,

i have a class and a class attribute log which is a logger object. In
the __del__() function i want to log a message but it fails even if i
use self.__class__. log.

The error i get is this:
Traceback (most recent call last):
File "C:\Python24\li b\logging\__ini t__.py", line 712, in emit
self.stream.wri te(fs % msg)
ValueError: I/O operation on closed file

So is there no way to use the logger object in a __del__
I wanted to use the message to clearly indicate in the logger file that
the instance had closed ok.

Regards,
Benedict

[Vinay Sajip]

flupke <flupke <at> nonexistingdoma in.com> writes:

Hi,

i have a class and a class attribute log which is a logger object. In
the __del__() function i want to log a message but it fails even if i
use self.__class__. log.

The error i get is this:
Traceback (most recent call last):
File "C:\Python24\li b\logging\__ini t__.py", line 712, in emit
self.stream.wri te(fs % msg)
ValueError: I/O operation on closed file

So is there no way to use the logger object in a __del__
I wanted to use the message to clearly indicate in the logger file that
the instance had closed ok.

It all depends. If your __del__ is being called via atexit() for application
cleanup, for example, logging may not be available to you because it has been
cleaned up beforehand.

The logging module registers an atexit() handler to flush and close handlers
before script termination.

Vinay Sajip

[flupke]

Vinay Sajip wrote:

flupke <flupke <at> nonexistingdoma in.com> writes:

Hi,

i have a class and a class attribute log which is a logger object. In
the __del__() function i want to log a message but it fails even if i
use self.__class__. log.

The error i get is this:
Traceback (most recent call last):
File "C:\Python24\li b\logging\__ini t__.py", line 712, in emit
self.stream.wri te(fs % msg)
ValueError: I/O operation on closed file

So is there no way to use the logger object in a __del__
I wanted to use the message to clearly indicate in the logger file that
the instance had closed ok.

It all depends. If your __del__ is being called via atexit() for application
cleanup, for example, logging may not be available to you because it has been
cleaned up beforehand.

The logging module registers an atexit() handler to flush and close handlers
before script termination.

Vinay Sajip

Thanks i was able to solve it using a function registered in both the
classes i used in that project.
Why would one use __del__ instead of atexit then especially if the calls
you make in __del__ are so unrelieable?

Regards,
Benedict