المعالجات والمنسّقات والمرشحات

المعالجات توجّه سجلات السجل

import logging

logger = logging.getLogger("myapp")
logger.setLevel(logging.DEBUG)

sh = logging.StreamHandler()
logger.addHandler(sh)

logger.info("Goes to console")

StreamHandler

import logging, sys

logger = logging.getLogger("out")
handler = logging.StreamHandler(sys.stdout)
logger.addHandler(handler)
logger.warning("printed to stdout")

FileHandler

import logging

logging.basicConfig(
    filename="app.log",
    filemode="a",
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(message)s"
)
logging.info("Persisted to disk")

RotatingFileHandler

from logging.handlers import RotatingFileHandler
import logging

handler = RotatingFileHandler(
    "app.log", maxBytes=1_000_000, backupCount=5
)
logging.getLogger().addHandler(handler)

TimedRotatingFileHandler

from logging.handlers import TimedRotatingFileHandler
import logging

handler = TimedRotatingFileHandler(
    "app.log", when="midnight", backupCount=7
)
logging.getLogger().addHandler(handler)

المنسّقات

import logging

fmt = logging.Formatter(
    fmt="%(asctime)s %(levelname)-8s %(name)s — %(message)s",
    datefmt="%Y-%m-%dT%H:%M:%S"
)
handler = logging.StreamHandler()
handler.setFormatter(fmt)
logging.getLogger().addHandler(handler)

التصفية على مستوى المعالج

import logging

logger = logging.getLogger("app")
logger.setLevel(logging.DEBUG)   # logger passes DEBUG+

err_handler = logging.FileHandler("errors.log")
err_handler.setLevel(logging.ERROR)  # only ERROR+
logger.addHandler(err_handler)

المرشّحات المخصصة

import logging

class SensitiveFilter(logging.Filter):
    def filter(self, record):
        return "password" not in record.getMessage().lower()

handler = logging.StreamHandler()
handler.addFilter(SensitiveFilter())
logging.getLogger().addHandler(handler)

إضافة حقول إضافية باستخدام مرشّح

import logging

class RequestIDFilter(logging.Filter):
    def __init__(self, request_id):
        self.request_id = request_id
    def filter(self, record):
        record.request_id = self.request_id
        return True

# fmt: "%(request_id)s %(message)s"

معالجات متعددة لمسجّل واحد

import logging

logger = logging.getLogger("multi")
logger.addHandler(logging.StreamHandler())             # console
logger.addHandler(logging.FileHandler("audit.log"))   # file
logger.setLevel(logging.INFO)
logger.info("Both destinations receive this")

تعطيل النشر

import logging

logger = logging.getLogger("mylib")
logger.propagate = False   # stays here, does not reach root
logger.addHandler(logging.StreamHandler())

تحقّق سريع

مراجعة