Why 4.5.5.64 & findcontours，return contours are tuple？

Python
1

4.5.5.64是新版本的大变动吗？
4.5.5.64的版本的findcontours，返回的contours是个tuple，之前都是列表的呀？

2

yes indeed it returns tuples now, there were changes in the python wrappers