logger chain in python

Question

I'm writing python package/module and would like the logging messages mention what module/class/function they come from. I.e. if I run this code: ``` import mymodule.utils.worker as worker w = worker.Worker() w.run() ``` I'd like to logging messages looks like this: ``` 2010-06-07 15:15:29 INFO mymodule.utils.worker.Worker.run <pid/threadid>: Hello from worker ``` How can I accomplish this? Thanks.

Accepted Answer

I tend to use the logging module in my packages/modules like so:

```
import logging
log = logging.getLogger(__name__)
log.info("Whatever your info message.")
```

This sets the name of your logger to the name of the module for inclusion in the log message. You can control where the name is by where `%(name)s` is found in the format string. Similarly you can place the pid with `%(process)d` and the thread id with `%(thread)d`. See the docs for all the options.

Formatting example:

```
import logging
logging.basicConfig(format="%(asctime)s %(levelname)s %(name)s %(process)d/%(threadName)s: %(message)s")
logging.getLogger('this.is.the.module').warning('Testing for SO')
```

Gives me:

```
2010-06-07 08:43:10,494 WARNING this.is.the.module 14980/MainThread: Testing for SO
```

logger chain in python

Solution

Problem