为什么这个监视程序脚本在我的家目录中无法工作？

Question

我正在写一个Python脚本，用来监控某个文件夹里的变化：

#!/usr/bin/env python3

import time
import os
import subprocess

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

class MyHandler(PatternMatchingEventHandler):
    patterns = ["*.txt", "*.html"]
    # targetDir = "/Users/kaiyin/Movies/screencasts_small/"

    def process(self, event):
        # p = subprocess.Popen(["/usr/local/bin/CocoaDialog", "bubble", "--title", "Watch folder", "--text", "New file" + event.src_path],
        #                  stdout=subprocess.PIPE,
        #                  stderr=subprocess.PIPE)
        # out, err = p.communicate()
        print("Something happened...")

    def on_created(self, event):
        print("Triggered...")
        self.process(event)
    def on_modified(self, event):
        print("Triggered...")
        self.process(event)

if __name__ == "__main__":
    arg = "/Users/kaiyin/Movies/screencasts"
    os.system("ls " + arg)
    observer = Observer()
    observer.schedule(MyHandler(), path=arg if arg else ".")
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()


# import os
# mystat = os.stat("/Users/kaiyin/Movies/screencasts")
# mystat[0]
# oct(mystat[0])
# int(oct(mystat[0]), 8)

问题是，文件的创建和修改根本没有触发处理函数，但如果我把arg = "/tmp/somefolder"改成其他路径，它就完全正常工作了。我现在很困惑。

这个文件夹的权限设置：

drwxr-xr-x  7 kaiyin  staff   238B Aug  7 17:03 /Users/kaiyin/Movies/screencasts/

Answer 1

我对这个 watchdog 模块不太了解，不过你可以用其他方法来检查目录。

while True:
    now = datetime.datetime.now()
    ago = now - datetime.timedelta(seconds=60)

    file_list = []
    for path in glob.glob(FILES + "/*.avi"):
        (mode, ino, dev, nlink, uid, gid, size, atime, mtime, ctime) = os.stat(path)

        if datetime.datetime.fromtimestamp(mtime) > ago:
            file_list.append(path)

    if(file_list): 
        ## process yuor list
        process(file_list)

    time.sleep(30)

这段代码会检查文件的修改时间，并把它放到 file_list 里。你可以扩展这个检查，把信息放到一个 dictionary（字典）里，这样就能检测到文件的变化。