Re: sum up numbers in a list

[Fredrik Lundh]

sharon kim wrote:

i have a list, for example;

>>L=[]
>>L.append('10')
>>L.append('15')
>>L.append('20')
>>len(L)

3

>>print L

['10', '15', '20']

is there a way to sum up all the numbers in a list? the number of
objects in the list is vary, around 50 to 60. all objects are 1 to 3
digit positive numbers.

the for-in statement is your friend:

S = 0
for item in L:
S += int(item)

it can also be used in-line (this is called a "generator expression"):

S = sum(int(v) for v in L)

or even hidden inside a built-in helper function:

S = sum(map(int, L))

</F>