Logging to file
For long-running programs, logging to the screen is not a very viable option. After running the code for hours, the oldest logged messages will be lost, and even if they were still available, it wouldn't be very easy to read all the logs or search through them.
Saving logs to a file allows for unlimited length (as far as our disk allows it) and enables the usage of tools, such as grep, to search through them.
By default, Python logging is configured to write to screen, but it's easy to provide a way to write to any file when logging is configured.
How to do it...
To test logging to a file, we are going to create a short tool that computes up to the nth Fibonacci number based on the current time. If it's 3:01 P.M., we want to compute only 1 number, while if it's 3:59 P.M., we want to compute 59 numbers.
The software will provide the computed numbers as the output, but we also want to log up to which number it computed and when it was run:
import logging, sys if __name__ == '__main__...
