import multiprocessing

def heavy_load_func(N, child_conn):
    '''function do heavy computing'''
    
    try:

        #do_some_heavy_computing
        return_value=99
        fp=open('wangjin.txt','r')
        fp.close()
        child_conn.send(return_value)  #return something
        
    except Exception as e:
        child_conn.send(e)  #将异常通过管道送出
        

if __name__=='__main__':
    '''main function'''
    try:
        parent_conn, child_conn = multiprocessing.Pipe()
        child_process = multiprocessing.Process(target=heavy_load_func, args=(10, child_conn))
        child_process.start()
        #child_process.join()
        child_return = parent_conn.recv()

        print('#####main try:',child_return,type(child_return),dir(child_return),child_return.args)
        print(str( child_return  ))
    except Exception as e:
        print('####main exception:',e)