Any time I see a use for lambda (typically only with the functional builtins), I just write a function instead. Two extra lines are worth it for the readability alone. You can also reuse a function, which makes more sense to me than potentially writing the same lambda multiple times.

I do like that the author used Python, even if it was only for the purpose of pseudocode. Python is, after all, "executable pseudocode". It's also the only language I really know in-depth.