Flask Framework Cookbook - Second Edition

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The information logged does not help much. It will be great to know when the issue was logged, with what level, which file caused the issue at what line number, and so on. This can be achieved using advanced logging formats. For this, we need to add a couple of statements to the configuration file; that is, my_app/__init__.py:

if not app.debug: 
    import logging     logging.basicConfig(level=logging.WARNING)
    from logging import FileHandler, Formatter 
    file_handler = FileHandler(app.config['LOG_FILE']) 
    app.logger.addHandler(file_handler) 
    file_handler.setFormatter(Formatter( 
        '%(asctime)s %(levelname)s: %(message)s ' 
        '[in %(pathname)s:%(lineno)d]' 
    )) 

In the preceding code, we added a formatter to file_handler, which will log the time, ...