Python

is and ==

is is identity testing, == is equality testing. what happens in your code would be emulated in the interpreter like this:

>>> a = 'pub'
>>> b = .join(['p', 'u', 'b'])
>>> a == b
True
>>> a is b
False

[1]

Access index in for loop

for idx, val in enumerate(ints):
   print(idx, val)

[2]