Help with cumulative sum

[J. Cliff Dyer]

If I gave you a list of numbers, could you come up with a summifier
function that returns another list of numbers that are a cumulative sum?
You've got the information in place to create a file

def summifier(nums):
    """Returns a list of numbers that are the running 
    sum totals of nums"""

    # ???

list_of_numbers = [1, 24, 34, 28, 4, 1]
cumulative_sum = summifier(list_of_numbers)
assert(cumulative_sum == [1, 25, 59, 87, 91, 92])

If you can come up with the summifier function, you're all set.  I gotta
say, though, this smells like homework.

Cheers,
Cliff


On Tue, 2009-09-08 at 12:29 -0700, Maggie wrote:
> Building on the code that I posted in one of the previous posts.. I
> need to find a cumulative sum of the file of the times in the test
> file:
> 
> here is the code i have:
> 
> #!/usr/bin/python
> 
> import os.path
> 
> #name of output file
> filename = "OUTPUT.txt"
> 
> #open the file
> test = open ("test.txt", "rU")
> 
> #read in all the data into a list
> readData = test.readlines()
> 
> count = 0
> 
> FILE = open(filename, "w")
> 
> for item in readData:
> 
>    count = count + 1
>    tmp_string = str(count) + '	' + item
>    print >> FILE, tmp_string,
> 
> else:
>    print 'The loop is finito'
> 
> -----
> 
> my test file is this
> 
> 23
> 241
> 34234
> 83
> 123
> 
> and I need to find a CUMULATIVE sum (or the running sum)...what would
> be the best way to go about that given the code i already have?
> 
> thank you all!