Python Sched用法及代碼示例

Sched模塊是標準庫，可用於創建機器人和其他監控和自動化應用程序。 sched 模塊實現了一個通用事件調度程序，用於在特定時間運行任務。它提供了類似於Windows或Linux中的任務調度程序的工具，但主要優點是與Python自己的sched模塊平台差異可以忽略。

例子：

# Python program for Creating  
# an event scheduler 
  
  
import sched 
import time 
  
  
# Creating an instance of the 
# scheduler class 
scheduler = sched.scheduler(time.time,  
                            time.sleep) 

調度程序實例可用的基本方法

• 調度程序.enter():事件可以安排在延遲後或在特定時間運行。為了延遲安排它們，enter()使用方法。
  

  用法： scheduler.enter(delay, priority, action, argument=(), kwargs={})

  參數：
  delay:代表延遲時間的數字
  priority:優先值
  action:調用函數
  argument:參數元組

  例子：

  
  import sched 
  import time 
    
  # instance is created 
  scheduler = sched.scheduler(time.time, 
                              time.sleep) 
    
  # function to print time  
  # and name of the event 
  def print_event(name): 
      print('EVENT:', time.time(), name) 
    
  # printing starting time 
  print ('START:', time.time()) 
    
  # first event with delay of 
  # 1 second 
  e1 = scheduler.enter(1, 1,  
                       print_event, ('1 st', )) 
    
  # second event with delay of 
  # 2 seconds 
  e1 = scheduler.enter(2, 1,  
                       print_event, (' 2nd', )) 
    
  # executing the events 
  scheduler.run() 

  輸出：

  START: 1580389814.152131
  EVENT: 1580389815.1548214 1 st
  EVENT: 1580389816.1533117  2nd
  

• 調度程序.enterabs() enterabs()time 將事件添加到調度程序的內部隊列中，因為run()調用調度器的方法，調度器隊列中的條目被一一執行。
  

  用法： scheduler.enterabs(time, priority, action, argument=(), kwargs={})

  參數：
  time:必須執行事件/操作的時間
  priority:事件的優先級
  action:構成事件的函數
  argument:事件函數的位置參數
  kwargs:事件函數的關鍵字參數字典

  例子：

  
  # library imported 
  import sched 
  import time 
    
  # instance is created 
  scheduler = sched.scheduler(time.time, 
                              time.sleep) 
    
  # function to print time and 
  # name of the event 
  def print_event(name): 
      print('EVENT:', time.time(), name) 
    
  # printing starting time 
  print ('START:', time.time()) 
    
  # event x with delay of 1 second 
  # enters queue using enterabs method 
  e_x = scheduler.enterabs(time.time()+1, 1, 
                           print_event,  
                           argument = ("Event X", )); 
    
  # executing the events 
  scheduler.run() 

  輸出：

  START: 1580389960.5845037
  EVENT: 1580389961.5875661 Event X
  

• 調度程序.cancel()從隊列中刪除該事件。如果該事件不是當前隊列中的事件，則此方法將引發ValueError.
  

  用法： scheduler.cancel(event)

  參數：
  event:應刪除的事件。

  
  import sched 
  import time 
    
    
  # instance is created 
  scheduler = sched.scheduler(time.time, 
                              time.sleep) 
    
  # function to print time and 
  # name of the event 
  def print_event(name): 
      print('EVENT:', time.time(), name) 
    
  # printing starting time 
  print ('START:', time.time()) 
    
  # first event with delay  
  # of 1 second 
  e1 = scheduler.enter(1, 1,  
                       print_event, 
                       ('1 st', )) 
    
    
  # second event with delay  
  # of 2 seconds 
  e2 = scheduler.enter(2, 1,  
                       print_event, 
                       (' 2nd', )) 
    
  # removing 1st event from  
  # the event queue 
  scheduler.cancel(e1) 
    
  # executing the events 
  scheduler.run() 

  輸出：

  START: 1580390119.54074
  EVENT: 1580390121.5439944  2nd
  

• 調度程序.empty()如果事件隊列為空，則返回 True。這不需要爭論。

  例子：

  
  import sched 
  import time 
    
    
  # instance is created 
  scheduler = sched.scheduler(time.time, 
                              time.sleep) 
    
  # function to print time  
  # and name of the event 
  def print_event(name): 
      print('EVENT:', time.time(), name) 
    
  # printing starting time 
  print ('START:', time.time()) 
    
  # checking if event queue is 
  # empty or not 
  print(scheduler.empty()) 
    
  # event entering into queue 
  e1 = scheduler.enter(2, 1, 
                       print_event, 
                       ('1 st', )) 
    
  # checking if event queue is  
  # empty or not 
  print(scheduler.empty()) 
    
  # executing the events 
  scheduler.run() 

  輸出：

  START: 1580390318.1343799
  True
  False
  EVENT: 1580390320.136075 1 st
  

• scheduler.queue隻讀屬性，按事件運行順序返回即將發生的事件的列表。每個事件都顯示為具有以下字段的命名元組：時間、優先級、操作、參數、kwargs。

  
  # library imported 
  import sched 
  import time 
    
  # instance is created 
  scheduler = sched.scheduler(time.time, 
                              time.sleep) 
    
  # function to print time  
  # and name of the event 
  def print_event(name): 
      print('EVENT:', time.time(), name) 
    
  # printing starting time 
  print ('START:', time.time()) 
    
  # event entering into queue 
  e1 = scheduler.enter(2, 1, 
                       print_event,  
                       ('1 st', )) 
    
  # printing the details of 
  # upcoming events in event queue 
  print(scheduler.queue) 
    
  # executing the events 
  scheduler.run() 

  輸出：

  START: 1580390446.8743565
  [Event(time=1580390448.8743565, priority=1, action=, argument=(‘1 st’, ), kwargs={})]
  EVENT: 1580390448.876916 1 st