Logging Configuration#

The magpylib-material-response package uses Loguru to emit informative messages about computation progress and debugging information.

Default Behavior#

Following the recommended pattern for libraries, the package is disabled at import time and produces no output until the user opts in. Importing the package never adds, removes or replaces any loguru sinks already configured by the host application.

Enabling Logging#

To see log messages from the library, call configure_logging():

from magpylib_material_response import configure_logging
from magpylib_material_response.demag import apply_demag

# Enable logging with default settings (INFO level, colored output to stderr)
configure_logging()

configure_logging() adds a sink that only receives records emitted from within the magpylib_material_response package. It is safe to call multiple times; each call replaces only the sink it added previously, leaving any other loguru sinks untouched.

Note

By default, loguru ships with a pre-installed sys.stderr sink (handler id 0). Because configure_logging() does not touch sinks it did not add, you may see each package record appear twice: once via loguru’s default handler and once via the sink added by configure_logging. To avoid this, remove the default handler before configuring:

from loguru import logger
logger.remove(0)
configure_logging()

Configuration Options#

Log Level#

configure_logging(level="DEBUG")  # detailed internal operations
configure_logging(level="WARNING")  # only warnings and errors
# Available: DEBUG, INFO, WARNING, ERROR, CRITICAL

Output Destination#

import sys

configure_logging(sink=sys.stdout)  # stdout instead of stderr
configure_logging(sink="/path/to/file.log")  # log file

Disable Colors and Time#

configure_logging(enable_colors=False)  # useful for log files
configure_logging(show_time=False)

Step Timing Threshold#

The library wraps long-running steps in a timelog context that emits a “Completed: …” record when the step exceeds a duration threshold. The default is 1.0 second.

# Log every step, regardless of duration:
configure_logging(min_log_time=0)

# Only log very long steps:
configure_logging(min_log_time=10)

This setting is also picked up by apply_demag, demag_tensor, filter_distance, and match_pairs whenever their own min_log_time argument is left at its default (None). Passing an explicit value to those functions still overrides the global setting for that call.

Environment Variables#

export MAGPYLIB_LOG_LEVEL=DEBUG
export MAGPYLIB_LOG_COLORS=false
export MAGPYLIB_LOG_TIME=false
export MAGPYLIB_LOG_MIN_TIME=0

Disabling Logging#

from magpylib_material_response import disable_logging

disable_logging()

This re-disables the package and removes only the sink previously added by configure_logging.

Custom Application-Side Configuration#

If your application already configures loguru, you do not need to call configure_logging() at all. Instead, simply enable the package and let your own sinks handle the records:

from loguru import logger

logger.enable("magpylib_material_response")
# your existing logger.add(...) sinks now also receive package records

Example Usage#

import magpylib as magpy
from magpylib_material_response import configure_logging
from magpylib_material_response.demag import apply_demag
from magpylib_material_response.meshing import mesh_Cuboid

configure_logging(level="INFO")

magnet = magpy.magnet.Cuboid(dimension=(0.01, 0.01, 0.02), polarization=(0, 0, 1))
magnet.susceptibility = 0.1

meshed = mesh_Cuboid(magnet, target_elems=1000, verbose=True)
apply_demag(meshed, inplace=True)