This comes from a discussion about whether to issue a syntax warning for one-tuples without parentheses.

Regardless of whether a warning is issued, the following code:

    ...
    a, b
    ...

Creates a tuple then discards it.

  LOAD_FAST                0 (a)
  LOAD_FAST                1 (b)
  BUILD_TUPLE              2
  POP_TOP

we could eliminate the creation of the tuple:

  LOAD_FAST                0 (a)
  LOAD_FAST                1 (b)
  POP_TOP
  POP_TOP