Source code for ax.utils.common.logger

#!/usr/bin/env python3
# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.

# pyre-strict

import logging
import os
from typing import Any


AX_ROOT_LOGGER_NAME = "ax"
DEFAULT_LOG_LEVEL: int = logging.INFO


[docs]class AxOutputNameFilter(logging.Filter): """This is a filter which sets the record's output_name, if not configured """
[docs] def filter(self, record: logging.LogRecord) -> bool: if not hasattr(record, "output_name"): # pyre-ignore[16]: Record supports arbitrary attributes record.output_name = record.name return True
[docs]def get_logger(name: str) -> logging.Logger: """Get an Axlogger. To set a human-readable "output_name" that appears in logger outputs, add `{"output_name": "[MY_OUTPUT_NAME]"}` to the logger's contextual information. By default, we use the logger's `name` NOTE: To change the log level on particular outputs (e.g. STDERR logs), set the proper log level on the relevant handler, instead of the logger e.g. logger.handers[0].setLevel(INFO) Args: name: The name of the logger. Returns: The logging.Logger object. """ logger = logging.getLogger(name) logger.addFilter(AxOutputNameFilter()) return logger
[docs]def build_stream_handler(level: int = DEFAULT_LOG_LEVEL) -> logging.StreamHandler: """Build the default stream handler used for most Ax logging. Sets default level to INFO, instead of WARNING. Args: level: The log level. By default, sets level to INFO Returns: A logging.StreamHandler instance """ console = logging.StreamHandler() console.setLevel(level=level) formatter = _build_stream_formatter() console.setFormatter(formatter) return console
[docs]def build_file_handler( filepath: str, level: int = DEFAULT_LOG_LEVEL ) -> logging.StreamHandler: """Build a file handle that logs entries to the given file, using the same formatting as the stream handler. Args: filepath: Location of the file to log output to. If the file exists, output will be appended. If it does not exist, a new file will be created. level: The log level. By default, sets level to INFO Returns: A logging.FileHandler instance """ if os.path.isfile(filepath): get_logger(__name__).warning( f"Log file ({filepath}) already exists, appending logs." ) logfile = logging.FileHandler(filepath) logfile.setLevel(level=level) formatter = _build_stream_formatter() logfile.setFormatter(formatter) return logfile
def _build_stream_formatter() -> logging.Formatter: """Default formatter for log messages. Add timestamps to log messages.""" return logging.Formatter( fmt="[%(levelname)s %(asctime)s] %(output_name)s: %(message)s", datefmt="%m-%d %H:%M:%S", ) # pyre-ignore (ignoring Any in argument and output typing) def _round_floats_for_logging(item: Any, decimal_places: int = 2) -> Any: """Round a number or numbers in a mapping to a given number of decimal places. If item or values in dictionary is not a number, returns it as it. """ if isinstance(item, float): return round(item, 2) elif isinstance(item, dict): return { k: _round_floats_for_logging(item=v, decimal_places=decimal_places) for k, v in item.items() } elif isinstance(item, list): return [ _round_floats_for_logging(item=i, decimal_places=decimal_places) for i in item ] elif isinstance(item, tuple): return tuple( _round_floats_for_logging(item=i, decimal_places=decimal_places) for i in item ) return item
[docs]def set_stderr_log_level(level: int) -> None: """Set the log level for stream handler, such that logs of given level are printed to STDERR by the root logger """ ROOT_STREAM_HANDLER.setLevel(level)
"""Sets up Ax's root logger to not propogate to Python's root logger and use the default stream handler. """ ROOT_LOGGER: logging.Logger = get_logger(AX_ROOT_LOGGER_NAME) ROOT_LOGGER.propagate = False # Uses a permissive level on the logger, instead make each # handler as permissive/restrictive as desired ROOT_LOGGER.setLevel(logging.DEBUG) ROOT_STREAM_HANDLER: logging.StreamHandler = build_stream_handler() ROOT_LOGGER.addHandler(ROOT_STREAM_HANDLER)