> ... confusing as hell to "newcomers". For example, when a list comprehension has multiple `for`s, what order are they nested in?

I get that this is just a rhetorical question to make a point about newcomers, and I do agree it's not immediately obvious, but for the record: you can imagine any "if"s and "for"s in a list comprehension are nested statements in the same order. So, for example, this:

   l = [
      y.foo()
      for x in my_list
      if x.blah() > 7
      for y in x.ys()
   ]

Is equivalent to this:

   l = []
   for x in my_list:
       if x.blah() > 7:
           for y in x.ys():
               l.append(y.foo())

So the least comprehension is basically in left to right order with the one exception of the actual expression to be added to the list (like y.foo() in the example above).