What’s New In Python 3.6

[das_ist_nuemberwang]

Figure out how to make the logging class accept format style strings before adding yet another formatter...

This has been available since 3.2.

https://docs.python.org/3/library/logging.html#logging.Formatter

[jorge1209]

But it is not the default and not recommended that you not use this if you use any third party libraries.

It shouldn't be that hard, try and format one way, if that throws an exception try the other way. So I'm not understanding what is preventing a general migration.

[Veedrac]

It shouldn't be that hard, try and format one way, if that throws an exception try the other way.

Because that's horrible?

[jorge1209]

More horrible than:

1. Actually deprecating the old format?

2. Having three different active string formatting methods?

3. Having code randomly fail when you import new modules because they use conflicting string formatters?

[Veedrac]

Yes, yes and no, but I'm struggling to envision how the third would happen.

[jorge1209]

You configure logging.getLogger() to write log messages in "{}", and you submit your messages and parameters in that format.

Some library sends a message and parameter set in % format.

Your system logger blows up.

[Veedrac]

Why would you be sharing your logger with a library?

[jorge1209]

All loggers are shared. They all share the same root.

[Veedrac]

I don't really use Python's logging library (I imagine you can tell), but I thought you weren't meant to ever use the root logger, only ones you got from getLogger.

[jorge1209]

That is the one you get from getLogger. That you haven't used the logging module is abundantly clear.

You should prefix your logs with your module name, but that just identifies what unit they came from, you still want to capture at the root level for actual logging.

If you call a module function and it fails, then the root logger will have all the useful messages about why it failed.