Quick Looper

A simple polling style loop, run in a separate thread.

Installation

Install from PyPI:

pip install quicklooper

How to use

Make a class that inherits from the Looper class, and override the main method with code to be run each loop. The loop period may be set by assigning a float value to the class variable _interval or by passing the interval keyword arg to the Looper.__init__ method.

Override the on_start_up and on_shut_down methods to add any code to be run before the first loop, and after the final loop when stop is called.

Example of a basic app which polls the /printfiles directory for new files to print:

from quicklooper import Looper


class PrintMonitor(Looper):
    _interval = 10.0

    def __init__(self, directory: str):
        self.directory: str = directory
        self._printed_files: Set[str] = set()

    def on_start_up():
        self._printed_files = {file for file in os.listdir(self.directory)}

    def main():
        for file in os.listdir(self.directory):
            send_to_printer(file)  # implementation not shown
            self._printed_files.add(file)


if __name__ == '__main__':
    print_monitor = PrintMonitor('/printfiles')
    print_monitor.start()

When print_montitor.start() is called, the app runs on_start_up method, and then calls main every ten seconds to scan for new files to print.

Call stop to exit the loop immediately.