some initial function like

  v = setup()
  if v == 1:
    side_effect_1()
  elif v > 1:
    side_effect_1()
    side_effect_2(v)
  else:
    raise Exception()

then we can "refactor"

  v = setup()
  if v < 1:
    raise Exception()
  
  side_effect_1()
  if v > 1:
    side_effect_2(v)

i know that this might seem "dumb" that the code was ever setup the first way but code can grow into that shape pretty easily. this refactor "removes" the v==1 branch. this new code also follows the "early return" pattern, which improves readability.