Pyspark学习之Broadcast广播变量

Broadcast广播变量的使用规则：

     1.可以使用SparkContext.broadcast([初始值])创建
     2.使用 .value的方法来读取广播变量的值
     3.Broadcast广播变量被创建后不能修改

 

broadcast方法

    def broadcast(self, value):
        """
        Broadcast a read-only variable to the cluster, returning a
        L{Broadcast}
        object for reading it in distributed functions. The variable will
        be sent to each cluster only once.
        """
        return Broadcast(self, value, self._pickled_broadcast_vars)

broadcast用法

broadcast(value)
Broadcast a read-only variable to the cluster, returning a L{Broadcast} object for reading it in distributed functions. The variable will be sent to each cluster only once.