"Donald Bedsole" <drbeds...@gmail.com> wrote
most part. But, could someone make sure I'm understanding this one
expression correctly?
not (False and True)
Python evaluates it as "True"
Is it because:
1)You evaluate what's in the parentheses first. A thing can not be
false and true at the same time, so the answer is false.
2)However, the "not" outside the parentheses flips the meaning of
what
is inside the parentheses, so false becomes "True." ?
Absolutely correct. Well done.
Boolean algebra can be a weird thing to get your head around
the first time you come across it :-)
Here are some of the standard rules:
True and thing = thing
False and thing = False
True or thing = True
False or thing = thing
And perhaps most bizarre of all:
not(X or Y) = not X and not Y
not(X and Y) = not X or not Y
HTH,
--
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/
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