Source code for enpt.utils.logging

# -*- coding: utf-8 -*-

# EnPT, EnMAP Processing Tool - A Python package for pre-processing of EnMAP Level-1B data
#
# Copyright (C) 2018-2024 Karl Segl (GFZ Potsdam, segl@gfz-potsdam.de), Daniel Scheffler
# (GFZ Potsdam, danschef@gfz-potsdam.de), Niklas Bohn (GFZ Potsdam, nbohn@gfz-potsdam.de),
# Stéphane Guillaso (GFZ Potsdam, stephane.guillaso@gfz-potsdam.de)
#
# This software was developed within the context of the EnMAP project supported
# by the DLR Space Administration with funds of the German Federal Ministry of
# Economic Affairs and Energy (on the basis of a decision by the German Bundestag:
# 50 EE 1529) and contributions from DLR, GFZ and OHB System AG.
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version. Please note the following exception: `EnPT` depends on tqdm, which
# is distributed under the Mozilla Public Licence (MPL) v2.0 except for the files
# "tqdm/_tqdm.py", "setup.py", "README.rst", "MANIFEST.in" and ".gitignore".
# Details can be found here: https://github.com/tqdm/tqdm/blob/master/LICENCE.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with this program. If not, see <https://www.gnu.org/licenses/>.

"""EnPT logging module containing logging related classes and functions."""

import logging
import os
import warnings
import sys
from io import StringIO  # Python 3 only

__author__ = 'Daniel Scheffler'


[docs] class EnPT_Logger(logging.Logger): """Class for the EnPT logger.""" def __init__(self, name_logfile: str, fmt_suffix: any = None, path_logfile: str = None, log_level: any = 'INFO', append: bool = True) -> None: """Return a logging.logger instance pointing to the given logfile path. :param name_logfile: :param fmt_suffix: if given, it will be included into log formatter :param path_logfile: if no path is given, only a StreamHandler is created :param log_level: the logging level to be used (choices: 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL'; default: 'INFO') :param append: <bool> whether to append the log message to an existing logfile (1) or to create a new logfile (0); default=1 """ # private attributes self._captured_stream = '' # attributes that need to be present in order to unpickle the logger via __setstate_ self.name_logfile = name_logfile self.fmt_suffix = fmt_suffix self.path_logfile = path_logfile self.log_level = log_level super(EnPT_Logger, self).__init__(name_logfile) self.path_logfile = path_logfile self.formatter_fileH = logging.Formatter('%(asctime)s' + (' [%s]' % fmt_suffix if fmt_suffix else '') + ' %(levelname)s: %(message)s', datefmt='%Y/%m/%d %H:%M:%S') self.formatter_ConsoleH = logging.Formatter('%(asctime)s' + (' [%s]' % fmt_suffix if fmt_suffix else '') + ': %(message)s', datefmt='%Y/%m/%d %H:%M:%S') if path_logfile: # create output directory while not os.path.isdir(os.path.dirname(path_logfile)): try: os.makedirs(os.path.dirname(path_logfile)) except OSError as e: if e.errno != 17: raise else: pass # create FileHandler fileHandler = logging.FileHandler(path_logfile, mode='a' if append else 'w') fileHandler.setFormatter(self.formatter_fileH) fileHandler.setLevel(log_level) else: fileHandler = None # create StreamHandler self.streamObj = StringIO() streamHandler = logging.StreamHandler(stream=self.streamObj) streamHandler.setFormatter(self.formatter_fileH) streamHandler.set_name('StringIO handler') # create ConsoleHandler for logging levels DEGUG and INFO -> logging to sys.stdout consoleHandler_out = logging.StreamHandler(stream=sys.stdout) # by default it would go to sys.stderr consoleHandler_out.setFormatter(self.formatter_ConsoleH) consoleHandler_out.set_name('console handler stdout') consoleHandler_out.setLevel(log_level) consoleHandler_out.addFilter(LessThanFilter(logging.WARNING)) # create ConsoleHandler for logging levels WARNING, ERROR, CRITICAL -> logging to sys.stderr consoleHandler_err = logging.StreamHandler(stream=sys.stderr) consoleHandler_err.setFormatter(self.formatter_ConsoleH) consoleHandler_err.setLevel(logging.WARNING) consoleHandler_err.set_name('console handler stderr') self.setLevel(log_level) if not self.handlers: if fileHandler: self.addHandler(fileHandler) self.addHandler(streamHandler) self.addHandler(consoleHandler_out) self.addHandler(consoleHandler_err) def __getstate__(self): self.close() return self.__dict__ def __setstate__(self, ObjDict): """Define how the attributes of EnPT_Logger are unpickled.""" self.__init__(ObjDict['name_logfile'], fmt_suffix=ObjDict['fmt_suffix'], path_logfile=ObjDict['path_logfile'], log_level=ObjDict['log_level'], append=True) ObjDict = self.__dict__ return ObjDict @property def captured_stream(self) -> str: """Return the already captured logging stream. NOTE: - set self.captured_stream: self.captured_stream = 'any string' """ if not self._captured_stream: self._captured_stream = self.streamObj.getvalue() return self._captured_stream @captured_stream.setter def captured_stream(self, string: str): assert isinstance(string, str), "'captured_stream' can only be set to a string. Got %s." % type(string) self._captured_stream = string
[docs] def close(self): """Close all logging handlers.""" # update captured_stream and flush stream self.captured_stream += self.streamObj.getvalue() for handler in self.handlers[:]: try: if handler.get_name() == 'StringIO handler': self.streamObj.flush() self.removeHandler(handler) # if not called with '[:]' the StreamHandlers are left open handler.flush() handler.close() except PermissionError: warnings.warn('Could not properly close logfile due to a PermissionError: %s' % sys.exc_info()[1]) except ValueError as e: if str(e) != 'I/O operation on closed file': raise if self.handlers[:]: warnings.warn('Not all logging handlers could be closed. Remaining handlers: %s' % self.handlers[:])
[docs] def view_logfile(self): """View the log file written to disk.""" with open(self.path_logfile) as inF: print(inF.read())
def __del__(self): self.close() def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.close() return True if exc_type is None else False
[docs] def close_logger(logger): """Close the handlers of the given logging.Logger instance. :param logger: logging.Logger instance or subclass instance """ if logger and hasattr(logger, 'handlers'): for handler in logger.handlers[:]: # if not called with '[:]' the StreamHandlers are left open try: logger.removeHandler(handler) handler.flush() handler.close() except PermissionError: warnings.warn('Could not properly close logfile due to a PermissionError: %s' % sys.exc_info()[1]) if logger.handlers[:]: warnings.warn('Not all logging handlers could be closed. Remaining handlers: %s' % logger.handlers[:])
[docs] def shutdown_loggers(): """Shutdown any currently active loggers.""" logging.shutdown()
[docs] class LessThanFilter(logging.Filter): """Filter class to filter log messages by a maximum log level. Based on http://stackoverflow.com/questions/2302315/ how-can-info-and-debug-logging-message-be-sent-to-stdout-and-higher-level-messag """ def __init__(self, exclusive_maximum, name=""): """Get an instance of LessThanFilter. :param exclusive_maximum: maximum log level, e.g., logger.WARNING :param name: """ super(LessThanFilter, self).__init__(name) self.max_level = exclusive_maximum
[docs] def filter(self, record): """Filter funtion. NOTE: Returns True if logging level of the given record is below the maximum log level. :param record: :return: bool """ # non-zero return means we log this message return True if record.levelno < self.max_level else False