Question

My data is tab delimited and looks like this:

Name   Count    Sample
Dog    .0001    1
Dog    .00003   1
Dog    .0001    2
Cat    .0004    1
Cat    .0002    1
Cat    .0003    2
Cat    .0002    2

After i define my variables unid as the first column merged with the 3rd column (ex Dog_1) and num as the Count for that line, i append each num into a dictionary under the unid (using Python 2.7), like so:

for line in K:
        sp = line.split("\t")
        name = sp[0]
        unid = sp[3][:-2] +"_"+ sp[0]
        num = int(Decimal(sp[1]))
        if not dict1.has_key(unid):
            dict1[unid] = []
        dict1[unid].append(num)

I try to sum it with this:

dictTot = sum(dict1.values())

But i get this error message:

TypeError: unsupported operand type(s) for +: 'int' and 'list'

How can I sum these values such that I can retrieve Cat_1: .0006, Cat_2: .0005 etc?

Sorry everyone, as I know my ? is not great. But as stated by Jacob below,
“dictTot = sum(sum(value) for value in dict1.values())” sums all of the sums, but what I am looking for is to sum each group of values under each key independently so I can find out how many Cats there are in sample 1 and so on. Perhaps sum is not right for this? Sorry, as evident I am not a Python extraordinaire.

Answer 1

I basically rewrote the whole thing…

K = "Dog    .0001    1\n  Dog    .00003   1\n  Dog    .0001    2\n  Cat    .0004   1\n  Cat    .0002    1\n  Cat    .0003    2\n  Cat    .0002    2"
dict1 = {}
for line in K.split("\n"):
    sp = line.split()
    name = sp[0]
    unid = "_".join([sp[0] , sp[2][-2:]])
    num = float(sp[1])
    if not dict1.has_key(unid):
        dict1[unid] = [num,]
    else :
        dict1[unid].append(num)
print(dict1)
dictTot = sum([sum(x) for x in dict1.values()])
print(dictTot)

the final dict is

{'Dog_2': [0.0001], 
 'Dog_1': [0.0001, 3e-05], 
 'Cat_1': [0.0004, 0.0002], 
 'Cat_2': [0.0003, 0.0002]}

the sum is

0.00133

the values are lists, so you want to loop them to sum individually.

EDIT

apparently now you want “Cat_1: .0006, Cat_2: .0005 etc”, so upon dict1, you can do

for key in dict1.iterkeys():
    dict1[key] = sum(dict1[key])

now dict1 becomes

{'Dog_2': 0.0001, 
 'Dog_1': 0.00013, 
 'Cat_1': 0.0006, 
 'Cat_2': 0.0005}