この世で最も役に立たない関数 by Python

"404 Blog Not Found:js/scheme/perl/ruby/C - この世で最も役に立たない関数
Pythonで書いてみた。多分py3kじゃ動かない。

def pointless():
  global pointless;
  print 'Turning off myself', pointless;
  del pointless.func_globals['pointless']

py3kだとこう。

def pointless():
  global pointless;
  print('Turning off myself', pointless)
  del pointless.__globals__['pointless']

動かすとこんな感じ。

>>> def pointless():
... global pointless;
... print 'Turning off myself', pointless;
... del pointless.func_globals['pointless']
...
>>> pointless()
Turning off myself
>>> pointless()
Traceback (most recent call last):
File "", line 1, in
NameError: name 'pointless' is not defined

あっちのコメント欄にこんなのがあるけど

def pointless(): global pointless; print 'Turning off myself', pointless; pointless=None

>>> def pointless(): global pointless; print 'Turning off myself', pointless; pointless=None
...
>>> pointless()
Turning off myself
>>> pointless()
Traceback (most recent call last):
File "", line 1, in
TypeError: 'NoneType' object is not callable

微妙に意味が違う。

もっとシンプルな方法(多分d:id:methaneさん)

def pointless():
  global pointless;
  print 'Turning off myself', pointless;
  del pointless

な〜んだ、del pointlessで消えるんだ。……ん？

>>> pointless == pointless.__globals__['pointless']
True

なるほど。マイリマシタ。