如何仅将特定事件与 Python 看门狗匹配

Question

I'm intending to use Python watchdog to handle a directory where files are written to, and I'm only interested in image files, trouble is I dont quite grok the code at this page . This is my attempt:

from watchdog.observers import Observer
from watchdog.events import PatternMatchingEventHandler

class Beat(PatternMatchingEventHandler):
     def on_create(self,event):
             print event.src_path

if __name__ == "__main__":
    patt = ['\w+[.]jpeg']
    event_handler = Beat(patterns=patt,ignore_directories=True,) 
    observer = Observer()
    path = "./"
    observer.schedule(event_handler, path, recursive=True)
    observer.start()

I'm trying to use the pattern matching class, but I'm getting nothing. How is it supposed to be used?

Answer 1

Based on the source code , fnmatch is being used under the hood. fnmatch can only do UNIX glob-style pattern matching. Which means you may have better luck with *.jpg than \\w+[.]jpeg

Answer 2

You can actually use the RegexMatchingEventHandler instead of PatternMatchingEventHandler to accomplish exactly what you want to do:

from watchdog.observers import Observer
from watchdog.events import RegexMatchingEventHandler  

class ExampleHandler(RegexMatchingEventHandler):
     def on_create(self, event):
             print(event.src_path)

if __name__ == "__main__":
    pattern = '\w+\.jpeg'
    event_handler = ExampleHandler(regexes=[pattern], ignore_directories=True) 
    observer = Observer()
    path = "./"
    observer.schedule(event_handler, path, recursive=True)
    observer.start()
    import time
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()

    observer.join()