pre-PEP for optional 'pass'

[Terry Reedy]

>(e.g. while debugging). Instead of just commenting out the code, one
>must also add a "pass" statement, and then try to remember to take it
 >out again when re-enabling the code.

If one *does* use 'pass' instead of a docstring as a placeholder, it
is *not* necessary to remove it (except for aesthetics).

def f():
  return 1
  pass

is perfectly legal, as is

def f():
  pass
  return 1

Terry J. Reedy