why does dead code costs time?

Steven D'Aprano steve+comp.lang.python at pearwood.info
Wed Dec 5 18:39:55 CET 2012


On Wed, 05 Dec 2012 17:34:57 +0000, Steven D'Aprano wrote:

> I believe that's a leftover from
> early Python days when None was not a keyword and could be reassigned.

Oops! Wrong copy and paste! Here's a simpler version:

[steve at ando ~]$ python1.5
Python 1.5.2 (#1, Aug 27 2012, 09:09:18)  [GCC 4.1.2 20080704 (Red Hat 
4.1.2-52)] on linux2
Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
>>> from dis import dis
>>> def h():
...     return None
...
>>> dis(h)
          0 SET_LINENO          1

          3 SET_LINENO          2
          6 LOAD_GLOBAL         0 (None)
          9 RETURN_VALUE
         10 LOAD_CONST          0 (None)
         13 RETURN_VALUE


The conclusion remains the same: calling LOAD_GLOBAL None is likely a 
fossil from ancient Python before it was a keyword.


-- 
Steven



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