I don't think that's fair. I thought the discussion of AVL trees was quite readable. The code is basic and straightforward, and that's what you want for something like that. It's about the algorithms, not about being pythonic -- it's about fundamentals. For that, this seems good to me (though I'll admit I haven't read a lot of it yet.)
"I don't want to read something because I don't like the writing style."
I personally can get behind that argument. As an author you have to incentivize the reader to engage with what you've written, that's the job of the writer, not the reader. If you, in this way, alienate some users (like the one you replied to) so be it, this is also a choice of the author. I personally can't read `def fun(a,b): ...`, I strongly prefer `def fun(a, b): ...` and hence I stopped reading as well.
the amazon comment section for any technical books are littered with comments like yours(and i have declined to purchase books based on these comments).
That you don't like the taste of no space after comma is a fair reason, but it is still a pedantic reason.
Personally I think the importance depends on the font face and particular letters used, and in your example it was entirely unimportant: I couldn't actually see the difference for a good while.
