首先安装pyinofity，pip install pyinotify
创建Event Processor
与linux下面的inotify事件机制类似，我们通过继承ProcessEvent来实现对inotify事件的重写，这里将事件名封装成process_事件名，例如IN_CREATE会经过Event Processor变成process_IN_CREATE。下面是所有的事件：
| Inotify Events | Description |
|---|---|
| IN_CREATE | File/directory created in watched directory |
| IN_OPEN | File/directory opened in watched directory |
| IN_ACCESS | File accessed |
| IN_ATTRIB | Attributes of file/directory changed (e.g. permissions, timestamp, etc.) |
| IN_CLOSE_NOWRITE | Non-writable file/directory closed |
| IN_DELETE | File/directory deleted from watched directory |
| IN_DELETE_SELF | File/directory being watched deleted |
| IN_IGNORED | File/directory no longer watched, deleted, or unmounted filesystem |
| IN_MODIFY | File/directory modified |
| IN_MOVE_SELF | File/directory moved. Must monitor destination to know destination path |
| IN_MOVED_FROM | File/directory moved from one watched directory to another |
| IN_MOVED_TO | Similar to IN_MOVED_FROM except for outgoing file/directory |
| IN_Q_OVERFLOW | Event queue overflowed |
| IN_UNMOUNT | Filesystem of watched file/directory unmounted from system |
下面将通过一个简短的例子来展示：
import os
import pyinotify
class EventProcessor(pyinotify.ProcessEvent):
_methods = ["IN_CREATE",
"IN_OPEN",
"IN_ACCESS",
"IN_ATTRIB",
"IN_CLOSE_NOWRITE",
"IN_CLOSE_WRITE",
"IN_DELETE",
"IN_DELETE_SELF",
"IN_IGNORED",
"IN_MODIFY",
"IN_MOVE_SELF",
"IN_MOVED_FROM",
"IN_MOVED_TO",
"IN_Q_OVERFLOW",
"IN_UNMOUNT",
"default"]
def process_generator(cls, method):
def _method_name(self, event):
print("Method name: process_{}()\n"
"Path name: {}\n"
"Event Name: {}\n".format(method, event.pathname, event.maskname))
_method_name.__name__ = "process_{}".format(method)
setattr(cls, _method_name.__name__, _method_name)
for method in EventProcessor._methods:
process_generator(EventProcessor, method)
watch_manager = pyinotify.WatchManager()
event_notifier = pyinotify.Notifier(watch_manager, EventProcessor())
watch_this = os.path.abspath("/home/vincent/software")
watch_manager.add_watch(watch_this, pyinotify.ALL_EVENTS)
event_notifier.loop()
这里我们可以看到，监控了一个文件夹/home/vincent/software，当往这个文件夹中复制一份文件时，将会打印出所有对应的事件。
Method name: process_IN_CREATE()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_CREATE
Method name: process_IN_OPEN()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_OPEN
Method name: process_IN_MODIFY()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_MODIFY
Method name: process_IN_MODIFY()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_MODIFY
Method name: process_IN_MODIFY()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_MODIFY
Method name: process_IN_CLOSE_WRITE()
Path name: /home/vincent/software/Anaconda3-2021.05-Linux-x86_64.sh
Event Name: IN_CLOSE_WRITE
可以看出来，他会记录下文件操作的每一步，包括文件创建IN_CREATE，文件打开IN_OPEN，文件修改IN_MODIFY，文件关闭IN_CLOSE_WRITE
Non-Blocking Loop非阻塞方式
上面的loop()的方式会阻塞进程，在loop后面的代码将不会被执行，这里有三种解决办法：
Notifier with a timeout 使用超时
在构造notifier时，timeout参数告诉Notifier以特定的时间间隔获取通知。
event_notifier = pyinotify.Notifier(watch_manager, EventProcessor(), timeout=10)
当使用超时时，应用程序将不会自动获得文件系统更改通知。需要在不同的时间显式调用event_notifier.process_events()和event_notifier.read_events()。也可以调用event_notifier.check_events()来检查是否有事件等待处理。
ThreadedNotifier不同线程
可以将程序放到另一个线程中，通过ThreadedNotifier而不是Notifier调用，然后通过event_notifier.start()启动
event_notifier = pyinotify.ThreadedNotifier(watch_manager, EventProcessor())
watch_this = os.path.abspath("notification_dir")
watch_manager.add_watch(watch_this, pyinotify.ALL_EVENTS)
event_notifier.start()
AsyncNotifier异步
可以通过异步实现：
event_notifier = pyinotify.AsyncNotifier(watch_manager, EventProcessor())
然后通过调用asyncore中的loop()函数实现：
import asyncore
asyncore.loop()
inotify的局限性也适用于pyinotify。例如，不监视递归目录;必须运行另一个inotify实例来跟踪子目录。尽管Python提供了一个方便的inotify接口，但与C实现的inotify相比，会导致性能下降。