Calling one method from another within same class in Python

问题

I am very new to python. I was trying to pass value from one method to another within the class. I searched about the issue but i could not get proper solution. Because in my code, "if" is calling class's method "on_any_event" that in return should call my another method "dropbox_fn", which make use of the value from "on_any_event". Will it work, if the "dropbox_fn" method is outside the class?

I will illustrate with code.

class MyHandler(FileSystemEventHandler):
 def on_any_event(self, event):
    srcpath=event.src_path
    print (srcpath, 'has been ',event.event_type)
    print (datetime.datetime.now())
    #print srcpath.split(' ', 12 );
    filename=srcpath[12:]
    return filename # I tried to call the method. showed error like not callable 

 def dropbox_fn(self)# Or will it work if this methos is outside the class ?
    #this method uses "filename"

if __name__ == "__main__":
  path = sys.argv[1] if len(sys.argv) > 1 else '.'
  print ("entry")
  event_handler = MyHandler()
  observer = Observer()
  observer.schedule(event_handler, path, recursive=True)
  observer.start()
  try:
     while True:
         time.sleep(1)
  except KeyboardInterrupt:
    observer.stop()
  observer.join()

The main issue in here is.. I cannot call "on_any_event" method without event parameter. So rather than returning value, calling "dropbox_fn" inside "on_any_event" would be a better way. Can someone help with this?

回答1:

To call the method, you need to qualify function with self.. In addition to that, if you want to pass a filename, add a filename parameter (or other name you want).

class MyHandler(FileSystemEventHandler):

    def on_any_event(self, event):
        srcpath = event.src_path
        print (srcpath, 'has been ',event.event_type)
        print (datetime.datetime.now())
        filename = srcpath[12:]
        self.dropbox_fn(filename) # <----

    def dropbox_fn(self, filename):  # <-----
        print('In dropbox_fn:', filename)

回答2:

To accessing member functions or variables from one scope to another scope (In your case one method to another method we need to refer method or variable with class object. and you can do it by referring with self keyword which refer as class object.

class YourClass():

    def your_function(self, *args):

        self.callable_function(param) # if you need to pass any parameter

    def callable_function(self, *params): 
        print('Your param:', param)

来源：https://stackoverflow.com/questions/25825693/calling-one-method-from-another-within-same-class-in-python