Inspired by https://gist.github.com/schnittstabil/9372911#file-isenabledfor_vs_class_benchmark-py

lazy_logging_benchmark.py

import logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("log")


def simple():
    if logger.isEnabledFor(logging.DEBUG):
        logger.debug('Stupid log message ' + ' '.join([str(i) for i in range(20)]))


class LazyJoin(object):
    def __init__(self, s=None, items=None):
        self.__call__(s, items)

    def __call__(self, s, items):
        self.s = s
        self.items = items

    def __str__(self):
        return self.s.join(self.items)


def no_lazy():
    logger.debug('Stupid log message %s', ' '.join([str(i) for i in range(20)]))


def original_lazy():
    logger.debug('Stupid log message %s',
                 LazyJoin(' ', (str(i) for i in range(20))))


def callable_lazy(lazy_log):
    logger.debug('Stupid log message %s', lazy_log(' ', (str(i) for i in range(20))))


def no_arguments_lazy(lazy_log):
    logger.debug('Stupid log message %s', lazy_log)


if __name__ == '__main__':
    import timeit
    print(min(timeit.repeat("simple()", setup="from __main__ import simple")))
    print(min(timeit.repeat("no_lazy()", setup="from __main__ import no_lazy")))
    print(min(timeit.repeat("original_lazy()", setup="from __main__ import original_lazy")))
    print(min(timeit.repeat("callable_lazy(lazy_log)", setup="from __main__ import callable_lazy, LazyJoin; "
                                                             "lazy_log = LazyJoin()")))
    print(min(timeit.repeat("no_arguments_lazy(lazy_log)",
                            setup="from __main__ import no_arguments_lazy, LazyJoin; "
                                  "lazy_log = LazyJoin(' ', (str(i) for i in range(20)))")))