Jerome Palayoor

How it works

The script uses the watchdog library to watch a folder in the background and react whenever a new file shows up.

event_handler = Handler()
observer = watchdog.observers.Observer()
observer.schedule(event_handler, watchpath, recursive=False)
observer.start()
observer.join()

observer.schedule tells watchdog which folder to watch, recursive=False means it only watches that top-level folder, not subfolders inside it. observer.join() keeps the script alive and listening indefinitely.

Handling a new file

Every time a new file appears in the watched folder, on_created fires.

def on_created(self,event):
    if not event.is_directory:
        time.sleep(10)
        try:
            endpoint = event.src_path.rindex('.')
            end = event.src_path[endpoint+1:]
            namepoint = event.src_path.rindex('\\')
            name = event.src_path[namepoint+1:]
            path = watchpath + '\\folders\\' + end + ' files\\'
            if not os.path.exists(path):
                os.makedirs(path)
            shutil.move(event.src_path,path + name)
        except:
            pass

The time.sleep(10) matters more than it looks. Browsers write a file to disk while it's downloading, and a "created" event can fire before the download is actually finished. Waiting 10 seconds gives the download time to complete before the script tries to move a file that's still being written to.

From there it's string slicing: find the last . to get the extension, find the last \ to get the filename, then build a destination path like Downloads\folders\pdf files\ and move the file there, creating the folder first if it doesn't exist yet.

Running in the background

The file extension is .pyw instead of .py, that runs the script without opening a console window. Combined with adding it to Windows startup, it just runs quietly in the background from boot, sorting downloads as they come in without needing to be manually started.