python找到旺旺子窗口后怎么推送消息？

import win32gui
import win32con
import sys


def setText(aString):
    """设置剪贴板文本"""
    w.OpenClipboard()
    w.EmptyClipboard()
    w.SetClipboardData(win32con.CF_UNICODETEXT, aString)
    w.CloseClipboard()

def openWangwAndSend(father,son,msg):
    setText(msg)
    fbox = win32gui.FindWindow(None,father)
    print(fbox);
    sbox = win32gui.FindWindowEx(fbox,0,None,son)
    print(son);
    win32gui.ShowWindow(sbox,1)
    win32gui.SendMessage(sbox, 258, 22, 0)
    win32gui.SendMessage(sbox, 770, 0, 0)

    win32gui.SendMessage(sbox, win32con.WM_KEYDOWN, win32con.VK_RETURN, 0)
    win32gui.SendMessage(sbox, win32con.WM_KEYUP, win32con.VK_RETURN, 0)
    win32gui.ShowWindow(sbox, 2)   

#发送旺旺群
father = u'阿里旺旺 - ****'
son=u'****'
openWangwAndSend(father,son,'for test~')


代码如上，print(son)这行，能打印出名称，但后面的打开窗口和发送消息一直不行，感觉没有定位到，求大神指教。