python字节流怎么转化成图片

import base64# 图片转字节def tu_zi_jie():    with open('jiu.png','rb') as fp:        tu = base64.b64encode(fp.read())    # 生成很长得一串字节流    print(tu)if __name__ == '__main__':    tu_zi_jie()

import base64# 字节转图片def zi_tu():# 这个就是把上面打印的字节流那过来进行转换图片# 因为转换后字符串很长所以我截取了一部分b_tu = b'iVBORw0KGgoAAAANS....UhEU'tu_b = base64.b64decode(b_tu)    with open('tu.png', 'wb') as fp:        fp.write(tu_b)if __name__ == '__main__':    tu_zi_jie()