samuelharmer · February 7, 2020 12:27
diff --git a/app.py b/app.py
 #!/usr/bin/env python3

 import os
 import datetime
 import operator
 import logging
 import logging.config
 from pathlib import Path
 from functools import reduce

 from ruamel.yaml import YAML
 from ruamel.yaml.compat import StringIO


 module_import_time = datetime.datetime.now(datetime.timezone.utc)


 def get_by_path(root, items):
    """Access a nested object in root by item sequence."""
    # https://stackoverflow.com/a/14692747/594137
    return reduce(operator.getitem, items, root)


 def set_by_path(root, items, value):
    """Set a value in a nested object in root by item sequence."""
    # https://stackoverflow.com/a/14692747/594137
    get_by_path(root, items[:-1])[items[-1]] = value


 def fix_up_log_filename(config_data):

    path_to_node = ["logging", "handlers", "file", "filename"]

    # Fix up the log file path by, …
    original = get_by_path(config_data, path_to_node)

    # … expanding any datetime formatting symbols in the string, …
    fixed = module_import_time.strftime(original)

    # … then translating it to an absolute path, relative to this script.
    fixed = Path(fixed)
    if fixed.is_absolute():
        fixed = fixed.absolute()
    else:
        fixed = (Path(__file__).parent / fixed).absolute()

    # Ensure the directory exists
    os.makedirs(fixed.parent, exist_ok=True)

    # Print the log file location so the user can find it
    print(f"Logging to {original} -> {fixed}")

    # And put it back into the configuration.
    set_by_path(config_data, path_to_node, str(fixed))


 def load_config(config_path):

    # First we load the configuration
    yaml = YAML()
    with open(config_path) as f:
        config_data = yaml.load(f)

    # Fix up anything in the logging file configuration
    fix_up_log_filename(config_data)

    # Apply configuration
    logging.config.dictConfig(config_data["logging"])
    logging.info(f"Configuration file: {config_path.absolute()}")

    # Format and dump configuration
    yaml.indent(mapping=2, sequence=4, offset=2)
    stream = StringIO()
    yaml.dump(config_data, stream)
    logging.debug(stream.getvalue())

    return config_data


 def boldly_go(config):
    import secrets

    species = config["Federation"]["Known Species"]

    for i in range(1, 11):
        stardate = secrets.randbelow(100000) / 10

        logging.debug(f"[Scene {i}]")
        logging.info(f"Captain's log. Stardate {stardate}.")

        if stardate < 5000:
            if stardate % 2 == 0:
                logging.debug(f"Boldly going where no one has gone before")
            else:
                logging.info(f"Entering the {secrets.choice(species)} system")
        else:
            logging.warning(f"The {secrets.choice(species)} are attacking!")

            if stardate < 9000:
                if stardate % 2 == 0:
                    logging.error("She cannae take any more, Cap'n!")
                else:
                    logging.error("She's gonna blow!")
            else:
                logging.critical("It was… fun. Oh, my.")


 if __name__ == "__main__":
    config = load_config(Path(__file__).parent / "app.yaml")
    logging.info("Configuration has finished loading.")
    boldly_go(config)
diff --git a/app.yaml b/app.yaml
 logging:
  version: 1
  formatters:
    brief:
      format: "%(asctime)s.%(msecs)03d %(levelname).1s%(levelname).1s %(message)s"
      datefmt: "%H:%M:%S"
    precise:
      format: "%(asctime)s.%(msecs)03d %(levelname).1s%(levelname).1s %(module)s %(process)d %(thread)d %(message)s"
      datefmt: "%Y-%m-%dT%H:%M:%S"
  handlers:
    console:
      class: logging.StreamHandler
      level: INFO
      formatter: brief
      stream: ext://sys.stdout
    file:
      class: logging.FileHandler
      level: DEBUG
      formatter: precise
      filename: logs/migrate.%Y%m%dT%H%M%S%z.txt
  root:
    # Leave this as NOTSET so all messages reach the handlers.
    level: NOTSET
    handlers:
      - console
      - file

 Federation:
  Known Species:
    - Borg
    - Ferengi
    - Gorn
    - Klingon
    - Romulan
    - Vulcan
diff --git a/Logging.md b/Logging.md
	#!/usr/bin/env python3

	import os
	import datetime
	import operator
	import logging
	import logging.config
	from pathlib import Path
	from functools import reduce

	from ruamel.yaml import YAML
	from ruamel.yaml.compat import StringIO


	module_import_time = datetime.datetime.now(datetime.timezone.utc)


	def get_by_path(root, items):
	"""Access a nested object in root by item sequence."""
	# https://stackoverflow.com/a/14692747/594137
	return reduce(operator.getitem, items, root)


	def set_by_path(root, items, value):
	"""Set a value in a nested object in root by item sequence."""
	# https://stackoverflow.com/a/14692747/594137
	get_by_path(root, items[:-1])[items[-1]] = value


	def fix_up_log_filename(config_data):

	path_to_node = ["logging", "handlers", "file", "filename"]

	# Fix up the log file path by, …
	original = get_by_path(config_data, path_to_node)

	# … expanding any datetime formatting symbols in the string, …
	fixed = module_import_time.strftime(original)

	# … then translating it to an absolute path, relative to this script.
	fixed = Path(fixed)
	if fixed.is_absolute():
	fixed = fixed.absolute()
	else:
	fixed = (Path(__file__).parent / fixed).absolute()

	# Ensure the directory exists
	os.makedirs(fixed.parent, exist_ok=True)

	# Print the log file location so the user can find it
	print(f"Logging to {original} -> {fixed}")

	# And put it back into the configuration.
	set_by_path(config_data, path_to_node, str(fixed))


	def load_config(config_path):

	# First we load the configuration
	yaml = YAML()
	with open(config_path) as f:
	config_data = yaml.load(f)

	# Fix up anything in the logging file configuration
	fix_up_log_filename(config_data)

	# Apply configuration
	logging.config.dictConfig(config_data["logging"])
	logging.info(f"Configuration file: {config_path.absolute()}")

	# Format and dump configuration
	yaml.indent(mapping=2, sequence=4, offset=2)
	stream = StringIO()
	yaml.dump(config_data, stream)
	logging.debug(stream.getvalue())

	return config_data


	def boldly_go(config):
	import secrets

	species = config["Federation"]["Known Species"]

	for i in range(1, 11):
	stardate = secrets.randbelow(100000) / 10

	logging.debug(f"[Scene {i}]")
	logging.info(f"Captain's log. Stardate {stardate}.")

	if stardate < 5000:
	if stardate % 2 == 0:
	logging.debug(f"Boldly going where no one has gone before")
	else:
	logging.info(f"Entering the {secrets.choice(species)} system")
	else:
	logging.warning(f"The {secrets.choice(species)} are attacking!")

	if stardate < 9000:
	if stardate % 2 == 0:
	logging.error("She cannae take any more, Cap'n!")
	else:
	logging.error("She's gonna blow!")
	else:
	logging.critical("It was… fun. Oh, my.")


	if __name__ == "__main__":
	config = load_config(Path(__file__).parent / "app.yaml")
	logging.info("Configuration has finished loading.")
	boldly_go(config)
	logging:
	version: 1
	formatters:
	brief:
	format: "%(asctime)s.%(msecs)03d %(levelname).1s%(levelname).1s %(message)s"
	datefmt: "%H:%M:%S"
	precise:
	format: "%(asctime)s.%(msecs)03d %(levelname).1s%(levelname).1s %(module)s %(process)d %(thread)d %(message)s"
	datefmt: "%Y-%m-%dT%H:%M:%S"
	handlers:
	console:
	class: logging.StreamHandler
	level: INFO
	formatter: brief
	stream: ext://sys.stdout
	file:
	class: logging.FileHandler
	level: DEBUG
	formatter: precise
	filename: logs/migrate.%Y%m%dT%H%M%S%z.txt
	root:
	# Leave this as NOTSET so all messages reach the handlers.
	level: NOTSET
	handlers:
	- console
	- file

	Federation:
	Known Species:
	- Borg
	- Ferengi
	- Gorn
	- Klingon
	- Romulan
	- Vulcan