Doesn’t Python treat all empty iterables as false tho? This isn’t unique to python, is it? (though I’m not a programmer…just a dude who writes scripts every now and then)
Not really, generators have weird truthiness, i don’t remember if they evaluate to true or false, but they cannot be checked for emptiness so they default to either always true or always false.
My point is that the second statement you presented can have the effect of evaluating emptiness of a Sequence (note: distinct from an Iterable), but that only holds true if the target of the conditional IS a sequence. I’m underlining the semantic difference that was elided as a result of falsey evaluation.
if isinstance(mylist, list) and not mylistProblem solved.
Or
if not mylist # check if list is emptyYou’re checking if
mylistis falsey. Sometimes that’s the same as checking if it’s empty, if it’s actually a list, but that’s not guaranteed.Doesn’t Python treat all empty iterables as false tho? This isn’t unique to python, is it? (though I’m not a programmer…just a dude who writes scripts every now and then)
Not really, generators have weird truthiness, i don’t remember if they evaluate to true or false, but they cannot be checked for emptiness so they default to either always true or always false.
My point is that the second statement you presented can have the effect of evaluating emptiness of a Sequence (note: distinct from an Iterable), but that only holds true if the target of the conditional IS a sequence. I’m underlining the semantic difference that was elided as a result of falsey evaluation.
Ok, help a noob out. What is the difference between a sequence and an iterable? Is a sequence immutable, like a tuple?
An iterable is just something that can be iterated over, like
range(10), or[1, 2, 3].A sequence on the other hand is a Collection that is reversible.
https://docs.python.org/3/library/collections.abc.html#collections-abstract-base-classes
I think you missed the joke 😅
I thought it was funny!