# This code is part of a Qiskit project.
#
# (C) Copyright IBM 2022, 2023.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.
"""Qiskit Nature Logging Utilities."""
from typing import Optional, Dict, List
import os
import sys
import logging as python_logging
class _DefaultStreamHandler(python_logging.StreamHandler):
"""Default stream Handler"""
def __init__(self):
"""
Initialize the handler.
"""
super().__init__(stream=sys.stdout)
self.setFormatter(python_logging.Formatter(fmt=QiskitNatureLogging.LOG_FORMAT))
[docs]class QiskitNatureLogging:
"""Qiskit Nature Logging.
A collection of utility methods encapsulating logging functions.
The most basic use is:
.. code-block:: python
import logging
from qiskit_nature import logging as nature_logging
nature_logging.set_levels_for_names(
{"qiskit_nature": logging.DEBUG, "qiskit": logging.DEBUG})
It will print to 'stdout' DEBUG formatted logs, for the domains included.
One can access current logging levels for domains:
.. code-block:: python
from qiskit_nature import logging as nature_logging
dict = nature_logging.get_levels_for_names(["qiskit_nature", "qiskit"])
The result dictionary key is the domain string and the value the logging level
Methods exist also to add, remove logging handler with formatter and one to write to a file:
.. code-block:: python
import logging
from qiskit_nature import logging as nature_logging
nature_logging.log_to_file(
{"qiskit_nature": logging.DEBUG, "qiskit": logging.DEBUG},
path="file.log", mode="w"
)
If mode is not given, 'append' mode is used.
"""
LOG_FORMAT = "%(asctime)s:%(name)s:%(levelname)s: %(message)s"
[docs] def get_levels_for_names(self, names: List[str]) -> Dict[str, int]:
"""Return logging levels for module names.
Args:
names: list of module names (qiskit_nature.second_q.drivers, qiskit_algorithms etc)
Returns:
Dictionary mapping names to effective level
"""
name_levels: Dict[str, int] = {}
for name in names:
name_levels[name] = python_logging.getLogger(name).getEffectiveLevel()
return name_levels
[docs] def set_levels_for_names(
self, name_levels: Dict[str, int], add_default_handler: bool = True
) -> None:
"""Set logging levels for module names.
Args:
name_levels: Dictionary of module names (qiskit_nature.second_q, qiskit_algorithms etc)
to desired level
add_default_handler: add or not the default stream handler
"""
names: List[str] = []
for name, level in name_levels.items():
names.append(name)
logger = python_logging.getLogger(name)
logger.setLevel(level)
logger.propagate = False
handlers = logger.handlers
if add_default_handler and not any(
isinstance(h, _DefaultStreamHandler) for h in handlers
):
self.add_handler(name, _DefaultStreamHandler())
[docs] def add_handler(
self,
name: str,
handler: python_logging.Handler,
formatter: Optional[python_logging.Formatter] = None,
) -> None:
"""Add handler and optional formatter to a module name.
Args:
name: module name
handler: Logging Handler
formatter: Logging Formatter
"""
logger = python_logging.getLogger(name)
if formatter is not None:
handler.setFormatter(formatter)
logger.addHandler(handler)
[docs] def remove_handler(self, name: str, handler: python_logging.Handler) -> None:
"""Remove handler from module.
Args:
name: module name
handler: Logging Handler
"""
logger = python_logging.getLogger(name)
handler.close()
logger.removeHandler(handler)
[docs] def remove_all_handlers(self, names: List[str]) -> None:
"""Remove all handlers from modules.
Args:
names: list of module names (qiskit_nature.second_q.drivers, qiskit_algorithms etc)
"""
for name in names:
logger = python_logging.getLogger(name)
handlers = logger.handlers.copy()
for handler in handlers:
self.remove_handler(name, handler=handler)
[docs] def remove_default_handler(self, names: List[str]) -> None:
"""Remove default handler from modules.
Args:
names: list of module names (qiskit_nature.second_q.drivers, qiskit_algorithms etc)
"""
for name in names:
logger = python_logging.getLogger(name)
handlers = logger.handlers.copy()
for handler in handlers:
if isinstance(handler, _DefaultStreamHandler):
self.remove_handler(name, handler=handler)
[docs] def log_to_file(
self, names: List[str], path: str, mode: str = "a"
) -> python_logging.FileHandler:
"""Logs modules to file.
Args:
names: list of module names (qiskit_nature.second_q.drivers, qiskit_algorithms etc)
path: file path
mode: file open mode. If it is not specified, 'a' is used to append
Returns:
The logging File handler used
"""
filepath = os.path.expanduser(path)
handler = python_logging.FileHandler(filepath, mode=mode)
formatter = python_logging.Formatter(fmt=QiskitNatureLogging.LOG_FORMAT)
for name in names:
self.add_handler(name, handler, formatter)
return handler
logging = QiskitNatureLogging()