Source code for ensembl.utils.logging

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"""Easy initialisation functionality to set an event logging system.

Examples:

    >>> import logging, pathlib
    >>> from ensembl.utils.logging import init_logging
    >>> logfile = pathlib.Path("test.log")
    >>> init_logging("INFO", logfile, "DEBUG")
    >>> logging.info("This message is written in both stderr and the log file")
    >>> logging.debug("This message is only written in the log file")

"""

from __future__ import annotations

__all__ = [
    "LogLevel",
    "init_logging",
    "init_logging_with_args",
]

import argparse
from datetime import datetime
import logging
from typing import Optional, Union

from ensembl.utils import StrPath

LogLevel = Union[int, str]


def formatTime(
    record: logging.LogRecord,
    datefmt: str | None = None,  # pylint: disable=unused-argument
) -> str:
    """Returns the creation time of the log record in ISO8601 format.

    Args:
        record: Log record to format.
        datefmt: Date format to use. Ignored in this implementation.
    """
    return datetime.fromtimestamp(record.created).astimezone().isoformat(timespec="milliseconds")




def init_logging(
    log_level: LogLevel = "WARNING",
    log_file: Optional[StrPath] = None,
    log_file_level: LogLevel = "DEBUG",
    msg_format: str = "%(asctime)s [%(process)s] %(levelname)-9s %(name)-13s: %(message)s",
) -> None:
    """Initialises the logging system.

    By default, all the log messages corresponding to `log_level` (and above) will be printed in the
    standard error. If `log_file` is provided, all messages of `log_file_level` level (and above) will
    be written into the provided file.

    Args:
        log_level: Minimum logging level for the standard error.
        log_file: Logging file where to write logging messages besides the standard error.
        log_file_level: Minimum logging level for the logging file.
        msg_format: A format string for the logged output as a whole. More information:
            https://docs.python.org/3/library/logging.html#logrecord-attributes

    """
    # Define new formatter used for handlers
    formatter = logging.Formatter(msg_format)
    formatter.formatTime = formatTime  # type: ignore[method-assign]
    # Configure the basic logging system, setting the root logger to the minimum log level available
    # to avoid filtering messages in any handler due to "parent delegation". Also close and remove any
    # existing handlers before setting this configuration.
    logging.basicConfig(level="DEBUG", force=True)
    # Set the correct log level and format of the new StreamHandler (by default the latter is set to NOTSET)
    logging.root.handlers[0].setLevel(log_level)
    logging.root.handlers[0].setFormatter(formatter)
    if log_file:
        # Create the log file handler and add it to the root logger
        file_handler = logging.FileHandler(log_file)
        file_handler.setLevel(log_file_level)
        file_handler.setFormatter(formatter)
        logging.root.addHandler(file_handler)





def init_logging_with_args(args: argparse.Namespace) -> None:
    """Processes the Namespace object provided to call `init_logging()` with the correct arguments.

    Args:
        args: Namespace populated by an argument parser.

    """
    args_dict = vars(args)
    log_args = {x: args_dict[x] for x in ["log_level", "log_file", "log_file_level"] if x in args_dict}
    init_logging(**log_args)