Output not understood!

Question

How and why is the output?

https://code.sololearn.com/cvYjTW18i55q/?ref=app

Answer 1

because ([]) is same as [] (empty list == False)

but [()] is True as not empty list (contains an empty tuple)...

tuple containing a list must be written: ([],) to explicitly mark parenthesis as a tuple with only one item (else parenthesis are evaluated as mathematical expression ^^)

Answer 2

I believe it's because in: [([]), [()]]

the value at the first index is: ([])
*** the parenthesis are treated as parenthesis NOT tuple
SO, the correct first index value is: [] (an empty list)

the second value is: [()] (a list w/ an empty tuple inside)

When checking bools, anything 0, None, or empty iterables are considered False. Any value is True.

So you get:
False
True

Answer 3

Slick not every time: don't believe that :D

Answer 4

For illustration you may output item and type:

l=[([]),[()], (), (1), (1,), []]
for i in l:
print(i, type(i), bool(i), sep=" ")

Answer 5

visph dang bro, so much faster than me every time

Answer 6

RuntimeERROR in fact, parenthesis always are treated as mathematical expression... and tuple require to be parenthesis only in some cases:

t = a, b

create a tuple...

also:

t = a,

but as list item, parenthesis are required to explicitly mark the tuple boundaries from list items boundaries (wich too use comma as separator) ;)