[SOLVED] Summing up elements in a list in python using a for loop

Summing up elements in a list in python using a for loop

While working on a program that creates bars out of sets of numbers in a list, I found that adding up items in my list doesn't work. I thought the best way to do this is just to make a for loop.

Here's my list:

phonelist = [[12,14,16,17,18],[16,23,54,64,32]]

And then I try to add this up with a for loop

numphone = 0
for x in len(phonelist[0]):
    numphone = numphone + x

Yet I get this error:

TypeError: 'int' object is not iterable

What should I do?

Solution

>>> phonelist = [[12,14,16,17,18],[16,23,54,64,32]]
>>> [sum(li) for li in phonelist]
[77, 189]
>>> sum([sum(li) for li in phonelist])
266

or:

>>> sum(sum(li) for li in phonelist)    # generator expression...
266

If you are trying to create individual categories, you can use a dict:

data={'Bar {}'.format(i):sum(li) for i, li in enumerate(phonelist, 1)}
data['Total']=sum(data.values())

print data
{'Bar 2': 189, 'Bar 1': 77, 'Total': 266}

Then if you want to produce a simple bar graph:

for bar in sorted(data.keys()):
    print '{}: {}'.format(bar, int(round(25.0*data[bar]/data['Total']))*'*')

Prints:

Bar 1: *******
Bar 2: ******************
Total: *************************