back testing a trading strategy with python

I am developing a trading strategy but need to back test properly. I am quite clear on what I need to be done, but I keep hitting roadblocks when trying to code myself. The concept is simple enough and the initial work should be straight forward, but we will need to add layers as we go, but overall, it is not very complex. If you have worked with python for finance or have any experience in writing trading software and backtesting and would like some more information, then please let me know