scrapy.logformatter.LogFormatter

Class for generating log messages for different actions. All methods must return a dictionary listing the parameters ``level``, ``msg`` and ``args`` which are going to be used for constructing the log message when calling ``logging.log``. Dictionary keys for the method outputs: * ``level`` is the log level for that action, you can use those from the `python logging library <https://docs.python.org/3/library/logging.html>`_ : ``logging.DEBUG``, ``logging.INFO``, ``logging.WARNING``, ``logging.ERROR`` and ``logging.CRITICAL``. * ``msg`` should be a string that can contain different formatting placeholders. This string, formatted with the provided ``args``, is going to be the long message for that action. * ``args`` should be a tuple or dict with the formatting placeholders for ``msg``. The final log message is computed as ``msg % args``. Users can define their own ``LogFormatter`` class if they want to customize how each action is logged or if they want to omit it entirely. In order to omit logging an action the method must return ``None``. Here is an example on how to create a custom log formatter to lower the severity level of the log message when an item is dropped from the pipeline:: class PoliteLogFormatter(logformatter.LogFormatter): def dropped(self, item, exception, response, spider): return { 'level': logging.INFO, # lowering the level from logging.WARNING 'msg': "Dropped: %(exception)s" + os.linesep + "%(item)s", 'args': { 'exception': exception, 'item': item, } }