Python logging and dump to json

The ** logging ** package that comes standard is easy to use, but it's reasonable. I feel like the file handler isn't killed until the script dies. The following is a simple example of personally unexpected behavior. (Maybe this is the correct behavior ... Tell me more!)

sample_logging.py

from datetime import datetime as dt
import os, logging
def main():
  for i in xrange(1,6):
    log = logging.getLogger()
    
    #i-th iteration directory
    dir_name = "dir_{0}".format(i)
    os.makedirs(dir_name)

    #Log file (want to create) for i-th repeat directory
    log_file_name = "{0}/lg_index{1}.log".format(dir_name, i)
    logging.basicConfig(level = logging.INFO,\
                        filename = log_file_name,\
                        format = "[%(name)s: %(levelname)s @ %(asctime)s] %(message)s")

    # log
    log.info('hoge')
    log.info('foo')
    log.info(dt.now().strftime('%Y%m%d%H%M%S))

As a feeling, in each directory of dir_1, dir_2, ..., dir_5 I wanted to write a log when I did something, but when I do this In the log file (dir_1 / lg_index1.log "of dir_1 where logging was set first All info (because level = logging.INFO in this case) is written out. (This usage may not be correct / cool in the first place.)

Countermeasure 1 (Handling file handlers / Isn't it too beautiful?)

I referred to this (* I've been squeezed by copying)

• http://stackoverflow.com/questions/24816456/python-logging-wont-shutdown

sample_logging_new.py

from datetime import datetime as dt
import os, logging
def main():
  for i in xrange(1,6):
    log = logging.getLogger()
    
    #i-th iteration directory
    dir_name = "dir_{0}".format(i)
    os.makedirs(dir_name)

    #Log file (want to create) for i-th repeat directory
    log_file_name = "{0}/lg_index{1}.log".format(dir_name, i)
    log.setLevel(logging.INFO)
    fh = logging.FileHandler(filename = log_file_name)
    formatter = logging.Formatter(
        fmt='"[%(name)s: %(levelname)s @ %(asctime)s] %(message)s"',
        datefmt='%Y-%m-%d %H:%M:%S')
    fh.setFormatter(formatter)
    log.addHandler(fh)    

    # log
    log.info('hoge')
    log.info('foo')
    log.info(dt.now().strftime('%Y%m%d%H%M%S))

    # close file handler
    log.removeHandler(fh)
    del log, fh

Countermeasure 2 (If you use a file handler anyway, write it out directly)

@shima__shima taught me.

• https://twitter.com/taki__taki__/status/602473227412054016

sample_logging_json.py

from datetime import datetime as dt
import os, json
def main():
  for i in xrange(1,6):
    #i-th iteration directory
    info = {} #Dictionary to put data
    dir_name = "dir_{0}".format(i)
    os.makedirs(dir_name)

    #Log file (want to create) for i-th repeat directory
    log_file_name = "{0}/lg_index{1}.log".format(dir_name, i)
    info['hoge'] = 0
    info['foo'] = 0
    info['bar'] = dt.now().strftime('%Y%m%d%H%M%S)
    
    #json file export
    with open(log_file_name, 'w') as f:
        json.dump(info, f)

I thought that I didn't have to use logging if I just wanted to write out information (parameters, time, etc.).