The Mastering Dyalog APL book is available as a free PDF, too. Though the paper version is more enjoyable, and serves as an excellent monitor stand in need, as well.

As a Scheme programmer, one of the first things I did when learning APL was to create a new REPL/environment in Chez Scheme called Sapling that replicated APL in Scheme using Scheme implementations of the primitives.

I quickly discovered that at least for my meager mind, there was no way to combine the two as one. I could use one within the other without trouble, but I couldn't mix the two easily.

If you're interested, the Co-dfns compiler is designed to integrate with existing languages. If your language has a C FFI, then you'll be able to integrate with Co-dfns compiled code. The workflow is basically for you to produce a namespace of the functions you want to use, and then you can compile them and link against that in your Python or C or C++ code. You can then just call those functions with the appropriate arrays and things are a go. The main then you need to do is write a function to create a Co-dfns array to and from the data types you are using in your program.