Python Sched用法及代码示例

Sched模块是标准库，可用于创建机器人和其他监控和自动化应用程序。 sched 模块实现了一个通用事件调度程序，用于在特定时间运行任务。它提供了类似于Windows或Linux中的任务调度程序的工具，但主要优点是与Python自己的sched模块平台差异可以忽略。

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) 

调度程序实例可用的基本方法

• 调度程序.enter():事件可以安排在延迟后或在特定时间运行。为了延迟安排它们，enter()使用方法。
  

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

  参数：
  delay:代表延迟时间的数字
  priority:优先值
  action:调用函数
  argument:参数元组

  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() 

  输出：

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

• 调度程序.enterabs() enterabs()time 将事件添加到调度程序的内部队列中，因为run()调用调度器的方法，调度器队列中的条目被一一执行。
  

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

  参数：
  time:必须执行事件/操作的时间
  priority:事件的优先级
  action:构成事件的函数
  argument:事件函数的位置参数
  kwargs:事件函数的关键字参数字典

  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() 

  输出：

  START: 1580389960.5845037
  EVENT: 1580389961.5875661 Event X
  

• 调度程序.cancel()从队列中删除该事件。如果该事件不是当前队列中的事件，则此方法将引发ValueError.
  

  用法： scheduler.cancel(event)

  参数：
  event:应删除的事件。

  
  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() 

  输出：

  START: 1580390119.54074
  EVENT: 1580390121.5439944  2nd
  

• 调度程序.empty()如果事件队列为空，则返回 True。这不需要争论。

  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() 

  输出：

  START: 1580390318.1343799
  True
  False
  EVENT: 1580390320.136075 1 st
  

• scheduler.queue只读属性，按事件运行顺序返回即将发生的事件的列表。每个事件都显示为具有以下字段的命名元组：时间、优先级、操作、参数、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() 

  输出：

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