My master's degree completely failed to teach me how to test trading strategies.
So I spent 40 hours looking for Python backtesting libraries.
Then I started using the best ones.
But unlike my quant finance degree, these won't cost you $90,000.
Here they are for free.
Zipline
From Quantopian (acquired by Robinhood) the first to democratize quant trading, comes Zipline. It's a robust, fully-featured backtesting library which features slippage models, robust data handing and rich metrics.