how to direct python logger to Tkinker's Listbox?

Question

I have a simple app with a class representing a data structure and a class for GUI. I use a logger inside the first class:

class A(object):
    def __init__(self):
        self.logger = logging.getLogger(self.__class__.__name__)
        self.logger.info('creating new A object')

etc.

The GUI consists in one Tkinter window with a Listbox.

How can I direct the logs to the listbox? I would like to see the messages populate the list instead as they get logged instead of showing up in the console or log file.

How can I update the listbox while a method within the class is executed?

Answer 1

in this case it's probably best to implement your own logging.Handler:

from logging import Handler, getLogger

class ListboxHandler(Handler):
    def __init__(self, box):
        self._box = box
        Handler.__init__(self)

    def emit(self, record):
        r = self.format(record)
        self._box.insert(0, r)

# quick test:
target = [] # supports insert like Listbox :)
rootLogger = getLogger()
# add handler to the root logger here
# should be done in the config...
rootLogger.addHandler(ListboxHandler(target))
rootLogger.warn('test')
print(target)

this way you have full control over formatting, log levels etc. from your config.