Logging

This is a topic that is going to be useful for the next two chapters. Logging (https://docs.python.org/3/library/logging.html) helps with troubleshooting a problem. It helps with determining the root cause of a problem by tracing back through the sequence of events logged by the application. While we will be making extensive use of logging in the next two chapters, let's review logging using a simple application. In order to review logging, let's review it by making a POST request:

1. The first step in logging is setting the log file location and the log level:

       logging.basicConfig(format='%(asctime)s : %(levelname)s :
       %(message)s', filename='log_file.log', level=logging.INFO)

While initializing the logging class, we need to specify the format for logging information, errors, and so on to the file. In this case, the format is as follows:

       format='%(asctime)s : %(levelname)s : %(message)s'

The log messages are in the following format:

       2016-10-25 20:28:07,940 : INFO...