Why doesn't this custom logger use the root formatter?

The way I understand the logging documentation is that all calls to loggers that don't have handlers configured on them will eventually "fall through" to the root logger (and implicitly also use its formatter).

In the example below, neither "log" nor "mylog" are the root logger. Yet the call to log.error() uses the root logger's format, but mylog.error() doesn't. Why is that?

import logging

class MyLogger(logging.getLoggerClass()):
    pass

mylog = MyLogger("mytest")
log = logging.getLogger("test")
root = logging.getLogger()

h = logging.StreamHandler()
f = logging.Formatter(fmt="[%(levelname)s] %(message)s")
h.setFormatter(f)
root.addHandler(h)

log.error("Normal log")
mylog.error("Test log")

Output:

[ERROR] Normal log
Test log

(Background: I've written a custom logger that takes an extra object argument and augments the message with info about that object. Calls to that custom logger are sprinkled throughout several modules, alongside loggers acquired with logging.getLogger(). Of course I want those custom logs to use the same handlers and formatters I've set up centrally.)

From the documentation:

> Note that Loggers should NEVER be instantiated directly, but always through the module-level function logging.getLogger(name).

Instead of instantiating mylog by calling MyLogger, use logging.setLoggerClass to set the class used by getLogger to create mylog. Also, use logging.basicConfig to configure the logging system.

import logging

logging.basicConfig(format="[%(levelname)s] %(message)s")


class MyLogger(logging.getLoggerClass()):
    pass


root = logging.getLogger()
log = logging.getLogger("test")    
logging.setLoggerClass(MyLogger)
mylog = logging.getLogger("mytest")

log.error("Normal log")
mylog.error("Test log")

Thanks to chetner's tip I came to a simple solution. I added this:

root = logging.getLogger()
for h in root.handlers:
    mylog.addHandler(h)

It works at least in my test case.