"""Logging module supplying a general framework for logging in the PyDYNA
``pre`` service.
This module is built upon the `Python logging <https://docs.python.org/3/library/logging.html>`_
module. It is not intended to replace this Python module but rather to provide a way
for it and the PyDyna ``pre`` service to interact.
The loggers used in this PyDyna logging mdoule include the name of the instance,
which is intended to be unique. This name is printed in all the active
outputs and is used to track the different instances of the PyDyNA ``pre``
service.
Global logger
-------------
The global logger, named ``pydyna_global``, is created at
``ansys.dyna.core.__init__``. If you want to use the global logger,
you must call it at the top of your module:
.. code:: python
from ansys.dyna.core.pre import LOG
You can rename the global logger to avoid conflicts with other loggers (if any):
.. code:: python
from ansys.dyna.core.pre import LOG as logger
The default logging level of ``LOG`` is ``ERROR``. To change this to output
lower-level messages, you can use this code:
.. code:: python
LOG.logger.setLevel("DEBUG")
LOG.file_handler.setLevel("DEBUG") # If present.
LOG.stdout_handler.setLevel("DEBUG") # If present.
Alternatively, you can set the logging level of ``LOG`` to ``DEBUG``
with one line of code::
.. code:: python
LOG.setLevel("DEBUG")
Using the preceding line ensures that all the handlers are set to the input log level.
By default, this logger does not log to a file. If you want to log to a file,
you can add a file handler:
.. code:: python
import os
file_path = os.path.join(os.getcwd(), "pydyna.log")
LOG.log_to_file(file_path)
The preceding code sets the logger to also redirect to a file. If you want
to change the characteristics of the global logger from the beginning
of the execution, you must edit the ``__init__`` file in the
``ansys.dyna.core.pre`` directory.
To log using this logger, call the desired method as a normal logger.
Instance loggers
----------------
Every time an instance of the :class:`Mapdl <ansys.mapdl.core.mapdl._MapdlCore>`
class is created, a logger is created and stored in two places:
* ``_MapdlCore._log``: For backward compatibility.
* ``LOG._instances``: This field is a dictionary where the key is the name
of the created logger.
Instance loggers inheritate the ``pydyna_global`` output handlers and
logging level unless otherwise specified. Instance loggers work in a
similar way to the global logger. You can use the
:func:`log_to_file() <PymapdlCustomAdapter.log_to_file>` method to add
a file handler or the :func:`logger.Logging.setLevel` method to change
the log level.
Other loggers
~~~~~~~~~~~~~
You can create your own loggers using the Python ``logging`` module as
you would do in any other script. No conflicts between these loggers exist.
"""
from copy import copy
from datetime import datetime
import logging
import sys
import weakref
## Default configuration
[docs]
LOG_LEVEL = logging.DEBUG
[docs]
FILE_NAME = "pydyna.log"
# For convenience
[docs]
CRITICAL = logging.CRITICAL
## Formatting
[docs]
string_to_loglevel = {
"DEBUG": DEBUG,
"INFO": INFO,
"WARN": WARN,
"WARNING": WARN,
"ERROR": ERROR,
"CRITICAL": CRITICAL,
}
[docs]
class PymapdlCustomAdapter(logging.LoggerAdapter):
"""Adapter for keeping the reference to an MAPDL instance name dynamic.
Using the standard approach, extra parameters must be supplied
to the logger to indicate the MAPDL instance for which messages
must be logged.
With this class, you only have to specify the MAPDL instance
that you are referring to once.
"""
[docs]
level = None # This is maintained for compatibility with the ``supress_logging`` method, but it does nothing.
def __init__(self, logger, extra=None):
if extra is not None:
self.extra = weakref.proxy(extra)
else:
self.extra = None
self.file_handler = logger.file_handler
[docs]
self.std_out_handler = logger.std_out_handler
[docs]
def process(self, msg, kwargs):
kwargs["extra"] = {}
# These are the extra parameters sent to the log
kwargs["extra"]["instance_name"] = self.extra.name # here self.extra is the argument passed to the log records.
return msg, kwargs
[docs]
def log_to_file(self, filename=FILE_NAME, level=LOG_LEVEL):
"""Add a file handler to the logger.
Parameters
----------
filename : str, optional
Name of the file where logs are recorded. The default is ``FILE_NAME``.
level : str, optional
Level of logging. The default is ``LOG_LEVEL``, which causes all messages
to be recorded. For example, you can set the level of logging to ``DEBUG``.
"""
self.logger = addfile_handler(self.logger, filename=filename, level=level, write_headers=True)
self.file_handler = self.logger.file_handler
[docs]
def log_to_stdout(self, level=LOG_LEVEL):
"""Add a standard output handler to the logger.
Parameters
----------
level : str, optional
Level of logging record. The default is ``LOG_LEVEL``, which causes all messages
to be recorded. For example, you can set the level of logging to ``"DEBUG"``.
"""
if self.std_out_handler:
raise Exception("Stdout logger already defined.")
self.logger = add_stdout_handler(self.logger, level=level)
self.std_out_handler = self.logger.std_out_handler
[docs]
def setLevel(self, level="DEBUG"):
"""Change the log level of the object and the attached handlers.
Parameters
----------
level : str, optional
Level of logging record. The default is ``"DEBUG``.
"""
self.logger.setLevel(level)
for each_handler in self.logger.handlers:
each_handler.setLevel(level)
self.level = level
[docs]
class PymapdlPercentStyle(logging.PercentStyle):
def __init__(self, fmt, *, defaults=None):
self._fmt = fmt or self.default_format
self._defaults = defaults
def _format(self, record):
defaults = self._defaults
if defaults:
values = defaults | record.__dict__
else:
values = record.__dict__
# You can do here any changes that you want in record, such as adding a key.
# You could create an if here if you want conditional formatting, and even
# change the record.__dict__.
# Since we don't want to create conditional fields currently, it is fine to keep
# the same MSG_FORMAT for all of them.
# For the case of logging exceptions to the logger.
values.setdefault("instance_name", "")
return STDOUT_MSG_FORMAT % values
[docs]
class InstanceFilter(logging.Filter):
"""Ensures that the ``instance_name`` record always exists."""
[docs]
def filter(self, record):
if not hasattr(record, "instance_name"):
record.instance_name = ""
return True
[docs]
class Logger:
"""Provides the logger used for each PyDyna ``pre`` session.
This class allows you to add handlers to the logger to output to a file or
standard output.
Parameters
----------
level : int, optional
Logging level to filter the message severity allowed in the logger.
The default is ``logging.DEBUG``.
to_file : bool, optional
Whether to write log messages to a file. The default is ``False``.
to_stdout : bool, optional
Whether to write log messages to the standard output. The default is
``True``.
filename : str, optional
Name of the file to write log messages to if ``to_file=True``. The default
is ``FILE_NAME``.
Examples
--------
Demonstrate logger usage from an MAPDL instance mapdl. This logger is
automatically created when an MAPDL instance is created.
>>> from ansys.mapdl.core import launch_mapdl
>>> mapdl = launch_mapdl(loglevel='DEBUG')
>>> mapdl._log.info('This is a useful message')
INFO - - <ipython-input-24-80df150fe31f> - <module> - This is LOG debug message.
Import the global PYMAPDL logger and add a file output handler.
>>> import os
>>> from ansys.mapdl.core import LOG
>>> file_path = os.path.join(os.getcwd(), 'pymapdl.log')
>>> LOG.log_to_file(file_path)
"""
_level = logging.DEBUG
_instances = {}
def __init__(self, level=logging.DEBUG, to_file=False, to_stdout=True, filename=FILE_NAME):
"""Customized the logger for the PyDYNA ``pre`` service.
Parameters
----------
level : str, optional
Level of logging as defined in the ``logging`` package. The default is ``DEBUG``.
to_file : bool, optional
Whether to record the logs in a file. The default is ``False``.
to_stdout : bool, optional
Whether to output the logs to the standard output, which is the
command line. The default is ``True``.
filename : str, optional
Name of the file where the logs are recorded if ``to_file=True``. The default
is ``FILE_NAME``, in which case they are recorded in the
``'pymapdl.log'`` file.
"""
# create default main logger
[docs]
self.logger = logging.getLogger("pydyna_global")
self.logger.addFilter(InstanceFilter())
self.logger.setLevel(level)
self.logger.propagate = True
[docs]
self.level = self.logger.level # TODO: TO REMOVE
# Writing logging methods.
[docs]
self.debug = self.logger.debug
[docs]
self.info = self.logger.info
[docs]
self.warning = self.logger.warning
[docs]
self.error = self.logger.error
[docs]
self.critical = self.logger.critical
[docs]
self.log = self.logger.log
if to_file or filename != FILE_NAME:
# We record to file
self.log_to_file(filename=filename, level=level)
if to_stdout:
self.log_to_stdout(level=level)
# Using logger to record unhandled exceptions
self.add_handling_uncaught_expections(self.logger)
[docs]
def log_to_file(self, filename=FILE_NAME, level=LOG_LEVEL):
"""Add a file handler to logger.
Parameters
----------
filename : str, optional
Name of the file where the logs are recorded. The default
is ``FILE_NAME``, in which case they are recorded in the
``'pymapdl.log'`` file.
level : str, optional
Level of logging. The default is ``LOG_LEVEL``, in which
case ``'DEBUG'`` is used.
Examples
--------
Write to the ``pymapdl.log`` file in the current working directory.
>>> from ansys.mapdl.core import LOG
>>> import os
>>> file_path = os.path.join(os.getcwd(), 'pymapdl.log')
>>> LOG.log_to_file(file_path)
"""
self = addfile_handler(self, filename=filename, level=level, write_headers=True)
[docs]
def log_to_stdout(self, level=LOG_LEVEL):
"""Add a standard output handler to the logger.
Parameters
----------
filename : str, optional
Name of the file where the logs are recorded. The default
is ``FILE_NAME``, in which case they are recorded in the
``'pymapdl.log'`` file.
level : str, optional
Level of logging. The default is ``LOG_LEVEL``, in which
case ``'DEBUG'`` is used.
write_headers : bool, optional
Whether to write the headers to the file. The default is ``True``.
"""
self = add_stdout_handler(self, level=level)
[docs]
def setLevel(self, level="DEBUG"):
"""Change the log level of the object and the attached handlers.
Parameters
----------
level : str, optional
Level of logging. The default is ``'DEBUG'``.
"""
self.logger.setLevel(level)
for each_handler in self.logger.handlers:
each_handler.setLevel(level)
self._level = level
def _make_child_logger(self, suffix, level):
"""Create a child logger.
This method uses the ``getChild`` method or copies attributes between the
``pymapdl_global`` logger and the new one.
"""
logger = logging.getLogger(suffix)
logger.std_out_handler = None
logger.file_handler = None
if self.logger.hasHandlers:
for each_handler in self.logger.handlers:
new_handler = copy(each_handler)
if each_handler == self.file_handler:
logger.file_handler = new_handler
elif each_handler == self.std_out_handler:
logger.std_out_handler = new_handler
if level:
# The logger handlers are copied and changed the loglevel is
# the specified log level is lower than the one of the
# global.
if each_handler.level > string_to_loglevel[level.upper()]:
new_handler.setLevel(level)
logger.addHandler(new_handler)
if level:
if isinstance(level, str):
level = string_to_loglevel[level.upper()]
logger.setLevel(level)
else:
logger.setLevel(self.logger.level)
logger.propagate = True
return logger
[docs]
def add_child_logger(self, suffix, level=None):
"""Add a child logger to the main logger.
This child logger is more general than an instance logger, which is designed to
track the state of MAPDL instances.
If the logging level is in the arguments, a new logger with a reference
to the ``_global`` logger handlers is created instead of a child logger.
Parameters
----------
suffix : str
Name of the logger.
level : str, optional
Level of logging. The default is ``None``.
Returns
-------
logging.logger
Logger class.
"""
name = self.logger.name + "." + suffix
self._instances[name] = self._make_child_logger(self, name, level)
return self._instances[name]
def _add_mapdl_instance_logger(self, name, mapdl_instance, level):
if isinstance(name, str):
instance_logger = PymapdlCustomAdapter(self._make_child_logger(name, level), mapdl_instance)
elif not name: # pragma: no cover
instance_logger = PymapdlCustomAdapter(self._make_child_logger("NO_NAMED_YET", level), mapdl_instance)
else:
raise ValueError("You can only input 'str' classes to this method.")
return instance_logger
[docs]
def add_instance_logger(self, name, mapdl_instance, level=None):
"""Create a logger for an MAPDL instance.
The MAPDL instance logger is a logger with an adapter that adds
contextual information, such as the MAPDL instance name. This logger is
returned, and you can use it to log events as a normal logger. It is also
stored in the ``_instances`` field.
Parameters
----------
name : str
Name for the new logger.
mapdl_instance : ansys.mapdl.core.mapdl._MapdlCore
MAPDL instance object. This should contain the ``name`` attribute.
Returns
-------
ansys.mapdl.core.logging.PymapdlCustomAdapter
Logger adapter customized to add MAPDL information to the
logs. You can use this class to log events in the same
way you use the ``logger`` class.
Raises
------
Exception
You can only input strings as ``name`` to this method.
"""
count_ = 0
new_name = name
while new_name in logging.root.manager.__dict__.keys():
count_ += 1
new_name = name + "_" + str(count_)
self._instances[new_name] = self._add_mapdl_instance_logger(new_name, mapdl_instance, level)
return self._instances[new_name]
[docs]
def __getitem__(self, key):
if key in self._instances.keys():
return self._instances[key]
else:
raise KeyError(f"There is no instances with name {key}")
[docs]
def add_handling_uncaught_expections(self, logger):
"""Redirect the output of an exception to the logger."""
def handle_exception(exc_type, exc_value, exc_traceback):
if issubclass(exc_type, KeyboardInterrupt):
sys.__excepthook__(exc_type, exc_value, exc_traceback)
return
logger.critical("Uncaught exception", exc_info=(exc_type, exc_value, exc_traceback))
sys.excepthook = handle_exception
[docs]
def addfile_handler(logger, filename=FILE_NAME, level=LOG_LEVEL, write_headers=False):
"""Add a file handler to the input.
Parameters
----------
logger : logging.Logger or logging.Logger
Logger to add the file handler to.
filename : str, optional
Name of the output file. The default is ``FILE_NAME``.
level : str, optional
Level of logging. The default is ``LOG_LEVEL``.
write_headers : bool, optional
Whether to write the headers to the file. The default is ``False``.
Returns
-------
logger
Logger or Logger object.
"""
file_handler = logging.FileHandler(filename)
file_handler.setLevel(level)
file_handler.setFormatter(logging.Formatter(FILE_MSG_FORMAT))
if isinstance(logger, Logger):
logger.file_handler = file_handler
logger.logger.addHandler(file_handler)
elif isinstance(logger, logging.Logger):
logger.file_handler = file_handler
logger.addHandler(file_handler)
if write_headers:
file_handler.stream.write(NEW_SESSION_HEADER)
file_handler.stream.write(DEFAULT_FILE_HEADER)
return logger
[docs]
def add_stdout_handler(logger, level=LOG_LEVEL, write_headers=False):
"""Add a file handler to the logger.
Parameters
----------
logger : logging.Logger or logging.Logger
Logger to add the file handler to.
level : str, optional
Level of logging. The default is ``LOG_LEVEL``, in which
case ``""DEBUG" is used``.
write_headers : bool, optional
Whether to write the headers to the file. The default is ``False``.
Returns
-------
logger
Logger or Logger object.
"""
std_out_handler = logging.StreamHandler()
std_out_handler.setLevel(level)
std_out_handler.setFormatter(PymapdlFormatter(STDOUT_MSG_FORMAT))
if isinstance(logger, Logger):
logger.std_out_handler = std_out_handler
logger.logger.addHandler(std_out_handler)
elif isinstance(logger, logging.Logger):
logger.addHandler(std_out_handler)
if write_headers:
std_out_handler.stream.write(DEFAULT_STDOUT_HEADER)
return logger
[docs]
LOG = Logger(level=logging.ERROR, to_file=False, to_stdout=True)
LOG.debug("Loaded logging module as LOG")
