sum(iterable, start)

x : an iterable with numeric operands
start: initial value of sum

x = [10,20,30]
total = sum(x)
print ("x: ",x, "sum(x): ", total)

x = (10, -20, 10)
total = sum(x)
print ("x: ",x, "sum(x): ", total)

x = [10,20,30]
start = 5
total = sum(x, start)
print ("x: ",x, "start:", start, "sum(x, start): ", total)

x: [10, 20, 30] sum(x): 60
x: (10, -20, 10) sum(x): 0
x: [10, 20, 30] start: 5 sum(x, start): 65