How can I format warnings recorded using logging.captureWarnings?

Question

I used the following code to register alerts:

import logging logging.captureWarnings(True) formatter = logging.Formatter('%(asctime)s\t%(levelname)s\t%(message)s') console_handler = logging.StreamHandler() console_handler.setLevel(logging.DEBUG) console_handler.setFormatter(formatter) 

This works, however, my write formatter is not applied, and the warnings are as follows:

 WARNING:py.warnings:/home/joakim/.virtualenvs/masterload/local/lib/python2.7/site-packages/MySQL_python-1.2.3c1-py2.7-linux-x86_64.egg/MySQLdb/cursors.py:100: Warning: InnoDB: ROW_FORMAT=DYNAMIC requires innodb_file_per_table. 

instead of the expected format:

 2012-11-12 18:19:44,421 INFO START updating products 

How can I apply standard formatting to recorded warning messages?

Answer 1

You created a handler, but you never configured a logging module to use it:

 console_handler = logging.StreamHandler() console_handler.setLevel(logging.DEBUG) console_handler.setFormatter(formatter) 

You need to add this handler to the registrar; root registrar, for example:

 logging.getLogger().addHandler(console_handler) 

Alternatively, you can add a handler only to the alert logger; the captureWarnings() documentation states that it uses py.warnings for captured warnings:

 logging.getLogger('py.warnings').addHandler(console_handler) 

Instead of explicitly creating a handler and formatting, you can also just call basicConfig() to configure the root logger:

 logging.basicConfig(format='%(asctime)s\t%(levelname)s\t%(message)s', level=logging.DEBUG) 

The above basic configuration is the moral equivalent of the handler configuration you created.

Answer 2

logging.captureWarnings written to a log called py.warnings , so you need to add a handler to this logger:

 import logging logging.captureWarnings(True) formatter = logging.Formatter('%(asctime)s\t%(levelname)s\t%(message)s') console_handler = logging.StreamHandler() console_handler.setLevel(logging.DEBUG) console_handler.setFormatter(formatter) py_warnings_logger = logging.getLogger('py.warnings') py_warnings_logger.addHandler(console_handler) 

Answer 3

The documentation states that if the capture is True, warnings issued by the warning module will be redirected to the logging system. In particular, the warning will be formatted using warnings.formatwarning () and the resulting string logged in the log with the name "py.warnings" with the severity of WARNING.

Therefore i will try

 # get the 'py.warnings' logger log = logging.getLogger('py.warnings') # assign the handler to it log.addHandler(console_handler)