import paddle.fluid as fluid
main_prog = fluid.Program()
startup_prog = fluid.Program()
with fluid.program_guard(main_prog, startup_prog):
    data = fluid.layers.data(name="img", shape=[64, 784], append_batch_size=False)
    w = fluid.layers.create_parameter(shape=[784, 200], dtype='float32', name='fc_w')
    b = fluid.layers.create_parameter(shape=[200], dtype='float32', name='fc_b')
    hidden_w = fluid.layers.matmul(x=data, y=w)
    hidden_b = fluid.layers.elementwise_add(hidden_w, b)
place = fluid.CPUPlace()
exe = fluid.Executor(place)
exe.run(startup_prog)

# 示例一：用vars来指定加载变量。
path = "./my_paddle_vars"
var_list = [w, b]
fluid.io.save_vars(executor=exe, dirname=path, vars=var_list,
                   filename="vars_file")
fluid.io.load_vars(executor=exe, dirname=path, vars=var_list,
                   filename="vars_file")
# 加载w和b。它们被保存在'var_file'的文件中，所在路径为 "./my_paddle_model" 。

# 示例二：通过predicate来筛选加载变量。
def name_has_fc(var):
    res = "fc" in var.name
    return res

param_path = "./my_paddle_model"
fluid.io.save_vars(executor=exe, dirname=param_path, main_program=main_prog, vars=None, predicate=name_has_fc)
fluid.io.load_vars(executor=exe, dirname=param_path, main_program=main_prog, vars=None, predicate=name_has_fc)
#加载 `main_program` 中变量名包含 ‘fc’ 的所有变量
#此前所有变量应该保存在不同文件中