Uses python's awesome logging-library and configures it to write JSON-lines. In JSON-lines, each line in the log is a valid json-object. This makes the log easy to read with a machine.

pip install json-line-logger

There are three handy constructors for loggers: LoggerFile, LoggerStream, and LoggerStdout.

import json_line_logger

logger = json_line_logger.LoggerFile(path="test.log.jsonl")

logger.debug("This is a log message")

with json_line_logger.TimeDelta(logger=logger, name="some costly task"):
    result_of_a_costly_task = 1 + 1

json_line_logger.shutdown(logger=logger)

Yields a logfile test.log.jsonl which contains:

{"t":"1886-03-27T11:01:01.341", "l":"DEBUG", "m":"This is a log message"}
{"t":"1886-03-27T11:01:01.341", "l":"INFO", "m":"<TimeDelta name='some costly task' delta='2.1457672119140625e-06'/>"}