Hi, everyone can anybody elaborate me the usage of ‘not’ operator in boolean expressions. I mean, can we use two ‘not’ operators at a time. what is best about it. I’m waiting here
not is quite straightforward. It just inverts the boolean value of the expression to the right so that
not True evaluates to
not False evaluates to
True. You can use more than one
not operator on a single line though there’d be no benefit of chaining them
not not True for example is pointless. Combining them with other comparisons is common, like the following form:
if a > 3 and b is not None to create more complex logic statements.
If you’re curious about the order of evaluation then the docs are always a good shout- https://docs.python.org/3/reference/expressions.html#operator-precedence
ok thank you, plz look here and kindly points out, why it’s not working
if not credits >= 120 and gpa >= 2.0:
return “You do not meet either requirement to graduate!”
I’m finding difficulty here
Please see this topic:
if you include the information asked for in this topic, we are much better able to help you. Helping from a small snippet of code would involve a lot of guess work.
ok thannx. I’m gonna try it.
you can add this information (full code, exercise url) as a reply in this topic if you want Then we can help you further
thanx, @stetim94. I fixed it now. thanx for your help. I’ll need your guide again soon
NOT works on any value, not just booleans. The truth value coerces a boolean which NOT then toggles.
not 1 => False not 0 => True
Using a double not is the same as
not not 1 => True bool(1) => True
We can also use it in a toggle method…
a = 0 for _ in range(10): print (a) a = int(not(a))
We’ve seen above how the
is keyword can be used in combination, and it is common to see,
not in within a membership test.
x not in range(n)
As mentioned by @tgrtim, we can build some pretty sophisticated expressions that incorporate the
>>> x =  >>> len(x) is not 0 False >>>
Not like we would ever see that in code, but it does as promised.