The OA is quite customized, which is designed to be in the trading scenario. Not too difficult if you understand the long description. The last question is the easiest one and the second question is based on the first one. So you need to finish the first one then you can go to the second one.
python basics, object oriented programming with python, with statement, iterators, for loop, range, etc.
some programming questions about dfs and bfs, oo design questions, draw graph to explain the design
