simple-file-poller library released

The simple-file-poller Python 3 library has been released this week:

github.com/waikato-datamining/simple-file-poller

This library is aimed at Python projects that perform continuous processing of files, e.g., deep learning models that locate objects in images. These projects typically pick up files from one directory, make predictions, write the output in some format to another directory and then either move the input files to the output directory or simply delete them.

Instead of having to write this code for polling and moving over and over again, the simple-file-poller library allows you to plug in your file processing code via a function that you supply to a Poller object. Furthermore, you can also supply a function that can check whether files are valid and can be processed (e.g., image files).

The Poller class supports two polling modes: time-based and watchdog-based. The former waits for a specifie number of seconds between polls (if there were no files present). This simple approach can be used when the file processing is not time critical. The latter approach watches the input directory for files being created and then reacts to that immediately. This approach allows for very low latency processing, especially useful for processing pipelines.

Another feature is the ability to write any output to a temporary directory first, before moving it into the output directory. This avoids race conditions with other processes that further process the generated output files, as the files are guaranteed to have been fully written.

The following frameworks make use of the simple-file-poller now (and more will follow):