Just to be clear, all the answers so far are correct, but the reasoning behind them is not explained very well.
The sumall
variable is not yet a string. Parentheticals will not convert to a string (e.g. summ = (int(birthday[0])+int(birthday[1]))
still returns an integer. It looks like you most likely intended to type str((int(sumall[0])+int(sumall[1])))
, but forgot to. The reason the str()
function fixes everything is because it converts anything in it compatible to a string.