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From: Dennis Lee Bieber <wlfraed@ix.netcom.com>
Subject: Re: Short-circuit Logic
Date: Mon, 27 May 2013 21:36:30 -0400
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Xref: csiph.com comp.lang.python:46245

On Mon, 27 May 2013 13:08:34 -0700 (PDT), Ahmed Abdulshafy
<abdulshafy@gmail.com> declaimed the following in
gmane.comp.python.general:


> Thank you guys! you gave me valuable insights! But regarding my original post, I don't know why for the past two days I was looking at the code *only* this way>
>      if ( not allow_zero and abs(x) ) < sys.float_info.epsilon:
>
	Ah... That's covered under "operator precedence" and not the
short-circuit evaluation rule.

	Boolean "and" and "or" tend to come last in the parsing (bitwise &
and ^ come earlier, as I recall)

{Python 2.x}
>>> 5 & 2
0
>>> 5 ^ 2
7
>>> 5 and 2 
2
>>> 5 or 2
5
>>> 
>>> 5 & 2 and 5 ^ 2
0
>>> 5 & 2 or 5 ^ 2
7
>>> 5 ^ 2 and 5 & 2
0
>>> 5 ^ 2 or 5 & 2
7
>>> 
>>> 5 ^ (2 or 5) & 2
7
>>> 5 ^ (2 and 5) & 2
5
>>> 5 & (2 and 5) ^ 2
7
>>> 5 & (2 or 5) ^ 2
2
>>> 
-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
        wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/