python调用opencv，实现的界面随机绘画，其中包含了如何调用opencv的方法，值得新手借鉴。-python call opencv, to achieve a random drawing interface, which includes how to call a method of opencv worth novices learn.

实现多级目录遍历，随机产生目录层数，以及目录个数-Multi-level directory traversal, randomly generated directory levels, as well as catalog number