scope_guard

scope记录了作用域变量间的映射关系，类似于编程语言中的大括号。如果未调用此接口,则变量和变量名都会记录于全局scope。要切换作用域，就要用这个函数,下面是例子

import paddle.fluid as fluid
import numpy
new_scope = fluid.Scope()
with fluid.scope_guard(new_scope):
     fluid.global_scope().var("data").get_tensor().set(numpy.ones((1, 2)), fluid.CPUPlace())
data = numpy.array(new_scope.find_var("data").get_tensor())
print(data)  # [[1. 1.]]