Author here. Interesting to hear your perspective on this. I'm personally biased towards Flask, which I was trying to avoid when writing this article. Glad to see my thoughts on the two frameworks are reflected by other developers as well
--- [0] mutable vs non-mutable (strings and tuples) data structures for instance. This leads to inconsistencies: text = "hey there", text.sort() is not possible, data=[5, 7, 3], data.sort() is possible.
[1] since not every method returns a value we can't do method chaining. Ruby and JavaScript would allow me to do things like this: data.split.sort.first(). I used to do things like that in Mathematica years ago by postfix notation: f[data] // g // h (meaning: h(g(f(data)))). And Elixir allows this as well with data |> f |> g |> h. Can't do things like that in Python, have to create temp variables to capture intermediate results.