[Numpy-discussion] logical priority

Stephen Walton stephen.walton at csun.edu
Mon Feb 7 13:59:33 CST 2005


A probably bonehead question:  is it a known feature of Python that, in 
a logical operation, & has a higher priority than > or < ?  Or is it a 
quirk of numarray?

In [126]: a = arange(25)

In [127]: v=(a>9) & (a<13)

In [128]: v=a>9 & a<13
---------------------------------------------------------------------------
exceptions.RuntimeError                              Traceback (most 
recent call last)

/home/swalton/research/foukal/<console>

/usr/lib/python2.3/site-packages/numarray/generic.py in __nonzero__(self)
    475
    476     def __nonzero__(self):
--> 477         raise RuntimeError("An array doesn't make sense as a 
truth value.  Use any(a) or all(a).")
    478
    479     def __copy__(self):

RuntimeError: An array doesn't make sense as a truth value.  Use any(a) 
or all(a).





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