Chained Assignment in Python Bytecode

The author's expectations seem strange. Take another example:

    a = b = random.random()

“Since Python 3.6, every Python instruction has been given an odd number of arguments (even if it doesn't need any) so that the byte offsets are always even.”

I don’t think this is true. I think something like it is true for CPython (an argument isn’t added but the byte is kept for functions w no arg) but it’s not a statement about Python.

  a = b = []

  b = []
  a = b

I've seen stuff posted about chained assignment footguns in python regularly over the years, and it always surprises me. I don't think I've ever written them, or reviewed code that does. I don't think it'd occur to me to even think about writing a chained assignment.

Is chained assignment a pattern that comes from another language that people are applying to python?

Chained assignments are banned according to the style guide at my workplace. Too many opportunities for misuse. And if you insist on a one-liner assignment to two variables just use two statements separated by the semicolon. I challenge anyone to work out what this code does:

    a, b = b[a] = 1, [0, 1, 2, 3]

> list object is constructed once and assigned to both variables

Ummm no the list is constructed once and assigned to b and then b is assigned to a. It would be crazy semantics if `a = b = ...` meant `a` was assigned `...`.

Edit: I'm wrong it's left to right not right to left, which makes the complaint in the article even dumber.