# Add a code block here, if required>>>importthreading>>>x=threading.Barrier(parties=0.5)Traceback (mostrecentcalllast):File"<pyshell#0>",line1,in<module>x=Barrier(parties=0.5)ValueError:partiesmustbe>0

classBarrier:"""Implements a Barrier.    Useful for synchronizing a fixed number of threads at known synchronization    points.  Threads block on 'wait()' and are simultaneously awoken once they    have all made that call.    """def__init__(self,parties,action=None,timeout=None):"""Create a barrier, initialised to 'parties' threads.        'action' is a callable which, when supplied, will be called by one of        the threads after they have all entered the barrier and just prior to        releasing them all. If a 'timeout' is provided, it is used as the        default for all subsequent 'wait()' calls.        #if not isinstance(parties, int):        #        raise TypeError("parties must be an integer")        if parties < 1:                raise ValueError("parties must be > 0")        """self._cond=Condition(Lock())self._action=actionself._timeout=timeoutself._parties=partiesself._state=0# 0 filling, 1 draining, -1 resetting, -2 brokenself._count=0