常见的local variable 'x' referenced before assignment问题
https://blog.youkuaiyun.com/zhuzuwei/article/details/78234748
local variable 'xxx' referenced before assignment
https://blog.youkuaiyun.com/konglongaa/article/details/78401655
常见的local variable 'x' referenced before assignment问题
https://blog.youkuaiyun.com/zhuzuwei/article/details/78234748
local variable 'xxx' referenced before assignment
https://blog.youkuaiyun.com/konglongaa/article/details/78401655