Customised Logger

Triumvirate provides a customised logging.Logger, which can be accessed from the logger module.

from triumvirate.logger import setup_logger

Verbosity

When setting up the logger, one could choose the verbosity level by passing an integer or logging level variable. By default, the logging level is set at logging.INFO (see Logging Levels).

trv_logger = setup_logger(log_level=20)  # HINT: logging.INFO = 20

Log format

This logger behaves like a typical Python logger but with customised log message format [{local-timestamp}<YYYY-MM-DD HH:MM:SS> ({elapsed-time}<+HH:MM:SS>) {level}] {message}.

It also includes a C++ state indicator which is used to inform the user that the Cython-wrapped C++ backend is running.

trv_logger.info("This is a logged INFO-level message.")
trv_logger.debug("This is an unlogged DEBUG-level message.")
trv_logger.info(
    "This log entry indicates C++ backend is running.",
    cpp_state=True
)

[2023-10-03 16:13:22 (+00:00:00) INFO] This is a logged INFO-level message.
[2023-10-03 16:13:22 (+00:00:00) INFO] This log entry indicates C++ backend is running. (in C++)

Warning capture

The logger also captures warning messages and records them in a customised format.

# DEMO: capture warning with the logger.
import warnings
warnings.warn("This is a warning message captured as a log entry.")

[2023-10-03 16:13:22 (+00:00:00) WARN] This is a warning message captured as a log entry. (/var/folders/1_/q2lsr5v97z785g1fy4fh40sm0000gn/T/ipykernel_18426/2246887521.py:3:UserWarning --> "warnings.warn("This is a warning message captured as a log entry.")")

C++ backend logger

Some callables in Triumvirate calls C++ routines in the backend, which has its own logger. Any log-like entry in stdout with the format [{local-timestamp}<YYYY-MM-DD HH:MM:SS> ({elapsed-time}<+HH:MM:SS>) {level} C++] {message} (note the inclusion of ‘C++’) is a log message recorded by that logger.

By default this logger is alway present, but one can control its verbosity/logging level with the verbose parameter/attribute in a ParameterSet object passed to the callable.

Passing as an argument

Now, whenever a callable in Triumvirate accepts a logger argument, you can pass trv_logger above to it. You can modify it further to suit your needs (see logging).