Lie wrote: > On Mar 20, 4:18 am, Stef Mientki <[EMAIL PROTECTED]> wrote: >> hello, >> >> by accident I typed a double value test, >> and to my surprise it seems to work. >> Is this valid ? >> >> a = 2 >> b = 2 >> >> a == b == 2 >> >> thanks, >> Stef Mientki > > a == b == 2 > is equivalent to > a == b and b == 2 > except that b is only evaluated once for the whole comparison
Yes - there seems to be unanimity. Comparisons can be chained arbitrarily, e.g., x < y <= z is equivalent to x < y and y <= z, except that y is evaluated only once (but in both cases z is not evaluated at all when x < y is found to be false). Formally, if a, b, c, ..., y, z are expressions and opa, opb, ..., opy are comparison operators, then a opa b opb c ...y opy z is equivalent to a opa b and b opb c and ... y opy z, except that each expression is evaluated at most once. Colin W. -- http://mail.python.org/mailman/listinfo/python-list
