recurring_schedule.py

from functools import partial                                       
import sched                                                        
import time                                                         
                                                                    
                                                                    
class Scheduler:                                                    
    """                                                             
    A wrapper around a scheduler class providing                    
    a simple API for recurring events.                              
    """                                                             
                                                                    
    def __init__(self, scheduler=None):                             
        if scheduler is None:                                       
            scheduler = sched.scheduler(time.time, time.sleep)      
        self._scheduler = scheduler                                 
        self._recurring = dict()                                    
                                                                    
    def schedule(self, delay, func, recurring=False):               
        """                                                         
        Schedule a callable to be executed after `delay`.           
        If recurring is `True` the event is repeated.               
        To pass arguments to `func` use `functools.partial`.        
        """                                                         
        if recurring:                                               
            schedule = partial(                                     
                self.schedule, delay, func, recurring=True)         
            event = self._scheduler.enter(delay, 1, schedule)       
            self._recurring[event.action] = event                   
        self._scheduler.enter(delay, 1, func)                       
                                                                    
    def stop(self):                                                 
        """                                                         
        Cancel any recurring events.                                
        """                                                         
        while self._recurring:                                      
            try:                                                    
                self._scheduler.cancel(self._recurring.popitem()[1])
            except ValueError:                                      
                # Event has already executed.                       
                continue                                            
                                                                    
    def start(self):                                                
        """                                                         
        Start scheduled event execution.                            
        """                                                         
        self._scheduler.run(blocking=True)                          
                                                                    
                                                                    
if __name__ == "__main__":                                          
    ss = Scheduler()                                                
    ss.schedule(1, partial(print, 'foo'), recurring=True)           
    try:                                                            
        ss.start()                                                  
    except KeyboardInterrupt: