[Numpy-discussion] logical_and operator, &&, is missing?

Robert Kern robert.kern at gmail.com
Sat Jun 24 15:20:43 CDT 2006


Eric Firing wrote:
> It seems that the logical operators || and &&, corresponding to 
> logical_or and logical_and are missing; one can do
> 
> z = logical_and(x,y)
> 
> but not
> 
> z = x && y
> 
> Is there an inherent reason, or is this a bug?

Python does not have a && operator. It has an "and" keyword, but that cannot be 
overridden. If you know x and y to be boolean arrays, & and | work fine.

> z = (x == y)
> 
> works, and a comment in umathmodule.c.src suggests that && and || should 
> also:
> 
> /**begin repeat
> 
> #kind=greater, greater_equal, less, less_equal, equal, not_equal, 
> logical_and, logical_or, bitwise_and, bitwise_or, bitwise_xor#
> #OP=>, >=, <, <=, ==, !=, &&, ||, &, |, ^#
> **/

Those operators are the C versions that will be put in the appropriate places in 
the generated code. That is not a comment for documentation.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco





More information about the Numpy-discussion mailing list