I want bo create a function which returns sum of all passed arguments.
I found similar problem on forum, but It doesn't work with last case.
def sum_all(*args):
    sum = 0
    for num in args:
        if not str(num).isdigit():
            return False
        else:
            sum += int(num)
    return sum
This code work with first and second case, but return false on third case.
sum_all(2,-3)
# -1
sum_all([3,4,5])
# 12
sum_all(1,2,[3,4,5])
# false 
How can i make it work? To make it return 15 in last case? Thanks!
 
     
     
    