Search code examples
pythonloggingprintingpython-logging

In python, why use logging instead of print?

For simple debugging in a complex project is there a reason to use the python logger instead of print? What about other use-cases? Is there an accepted best use-case for each (especially when you're only looking for stdout)?

I've always heard that this is a "best practice" but I haven't been able to figure out why.

Solution

  • The logging package has a lot of useful features:

    • Easy to see where and when (even what line no.) a logging call is being made from.
    • You can log to files, sockets, pretty much anything, all at the same time.
    • You can differentiate your logging based on severity.

    Print doesn't have any of these.

    Also, if your project is meant to be imported by other python tools, it's bad practice for your package to print things to stdout, since the user likely won't know where the print messages are coming from. With logging, users of your package can choose whether they want to propogate logging messages from your tool or not.