On Sat, 07 Mar 2009 05:03:08 -0000, Grant Edwards <gra...@visi.com> wrote:
On 2009-03-07, Rhodri James <rho...@wildebst.demon.co.uk> wrote:
On Fri, 06 Mar 2009 15:34:08 -0000, Grant Edwards <inva...@invalid>
wrote:
On 2009-03-06, Fencer <no.s...@plz.ok> wrote:
Hi, I need a boolean b to be true if the variable n is not
None and not an empty list, otherwise b should be false.
I ended up with:
b = n is not None and not not n
I'd do it like this:
b = (n is not None) and (n != [])
The second comparison isn't actually necessary, since an
empty list is True and a non-empty one False.
b = (n is not None) and n
Putting the comparison in does make the code slightly less
"magic", though, so it's not a bad idea to do it!
Putting in the second comparison in makes the code match the
stated requirement. Otherwise you have to start making
assumptions about what n might be besides None or the empty
list.
The OP stated that we *could* assume that n was None or a
list, so I stand by what I said.
--
Rhodri James *-* Wildebeeste Herder to the Masses
--
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