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logging.basicConfig(force=False) on empty handler list never initializes Formatter and Handler #979
Description
Aiming to add minimalistic logging capabilities soon within starting phase of a micropythion program, one would call:
#minimalistic
logging.basicConfig(stream=stream.sys level=logging.DEBUG)
logger = logging.getLogger('thelog')
Aiming to get a fancy timestamp and information ordering, the call could look like:
# explicit formatting
log_fmt_mipy = "%(name)s - %(levelname)s - %(message)s"
log_fmt_dat_mipy = "%(asctime)s.%(msecs)03d"
logging.basicConfig(stream=stream.sys level=logging.DEBUG)
logger = logging.getLogger('thelog')
The Object "logger" as Logger instance on either case will NEVER get a working Handler and Formatter upon initialization. This is because logging.basicConfig() in (current) line 235 evaluates the list object Logger.handlers instead of the integer number Logger.hasHandlers().
NOTE: Initialization of a date format of type "asctime" within micropython, as shown in the code above, is not (yet) supported (by design) and thus requires explicit implementation efforts.
Activity
jamesquilty commentedon Oct 21, 2026
I took a look at this while fixing some other bugs and and found that
logging.basicConfig()creates and configures only the root logger (i.e. a logger named "root"). This is the same behaviour as the CPython standard library, described in the documentation and source code. I think this could be made a bit clearer in the MicroPythonlogging.basicConfig()function by:logger) to specific (root) which aligns with the CPython library;if force or not logger.hasHandlers():.I'll add these changes to the fixes I'm making.
The
time.strftime()function which Formatters require to process "asctime" is, in fact, implemented in micropython-lib/python-stdlib/time and the time module is de facto a requirement of the logging module. It's been noted in another Issue that perhaps this needs to be a little better documented.logging: Refactor basicConfig to clarify it configures the root logger.