CODEWITHSUNDEEP
pythonpython-2.7
Trying_hard
Trying_hard

Reputation: 9501

python add two list and createing a new list

lst1 = ['company1,AAA,7381.0 ', 'company1,BBB,-8333.0 ', 'company1,CCC,
3079.999 ', 'company1,DDD,5699.0 ', 'company1,EEE,1640.0 ',
       'company1,FFF,-600.0 ', 'company1,GGG,3822.0 ', 'company1,HHH,-600.0 ',
       'company1,JJJ,-4631.0 ', 'company1,KKK,-400.0 ']

lst2 =['company1,AAA,-4805.0 ', 'company1,ZZZ,-2576.0 ', 'company1,BBB,1674.0 ', 'company1,CCC,3600.0 ', 'company1,DDD,1743.998 ']

output I need == 

['company1,AAA,2576.0','company1,ZZZ,-2576.0 ','company1,KKK,-400.0 ' etc etc]

I need to add it similar product number in each list and move it to a new list. I also need any symbol not being added together to be added to that new list. I am having problems with moving through each list.

This is what I have:

h = [] 

z = []         

a = []        

for g in lst1:
    spl1 = g.split(",")
    h.append(spl1[1])
for j in lst2:
    spl2 = j.split(",")
    **if spl2[1] in h:
        converted_num =(float(spl2[2]) +float(spl1[2]))
        pos=('{0},{1},{2}'.format(spl2[0],spl2[1],converted_num))
        z.append(pos)**
    else:
        pos=('{0},{1},{2}'.format(spl2[0],spl2[1],spl2[2]))
        z.append(pos)

for f in z:
    spl3 = f.split(",")
    a.append(spl3[1])

for n in lst1[:]:
    spl4 = n.split(",")
    if spl4[1] in a:
        got = (spl4[0],spl4[1],spl4[2])
        lst1.remove(n)
smash = lst1+z #for i in smash:
for i in smash:
    print(i)

I am having problem iterating through the list to make sure I get all of the simliar product to a new list,(bold) and any product not in list 1 but in lst2 to the new list and vice versa. I am sure there is a much easier way.

Upvotes: 1

Views: 146

Answers (3)

DSM
DSM

Reputation: 353019

I second the use-a-dict suggestion. Because I'm lazy, I prefer to use a defaultdict because then I don't have to worry about checking to see whether a key exists. (You could also use a Counter here too.) In particular, assuming that you have to start and end with your lists:

from collections import defaultdict

data = defaultdict(float)

for line in lst1+lst2:
    name, code, value = line.split(",")
    data[name, code] += float(value)

newlist = ['{},{},{}'.format(key[0], key[1], val) for key, val in sorted(data.items())]

gives

>>> data
defaultdict(<type 'float'>, {('company1', 'HHH'): -600.0, ('company1', 'JJJ'): -4631.0,
('company1', 'KKK'): -400.0, ('company1', 'DDD'): 7442.998, ('company1', 'ZZZ'): -2576.0,
('company1', 'CCC'): 6679.999, ('company1', 'AAA'): 2576.0, ('company1', 'FFF'): -600.0,
('company1', 'GGG'): 3822.0, ('company1', 'EEE'): 1640.0, ('company1', 'BBB'): -6659.0})

and

>>> newlist
['company1,AAA,2576.0', 'company1,BBB,-6659.0', 'company1,CCC,6679.999',
'company1,DDD,7442.998', 'company1,EEE,1640.0', 'company1,FFF,-600.0', 
'company1,GGG,3822.0', 'company1,HHH,-600.0', 'company1,JJJ,-4631.0', 
'company1,KKK,-400.0', 'company1,ZZZ,-2576.0']

Upvotes: 2

Abhijit
Abhijit

Reputation: 63717

A complete solution to your problem

from collections import OrderedDict
lst1 = ['company1,AAA,7381.0 ', 'company1,BBB,-8333.0 ', 'company1,CCC, 3079.999 ', 
        'company1,DDD,5699.0 ', 'company1,EEE,1640.0 ', 'company1,FFF,-600.0 ', 
        'company1,GGG,3822.0 ', 'company1,HHH,-600.0 ', 'company1,JJJ,-4631.0 ', 
        'company1,KKK,-400.0 ']
lst2 =['company1,AAA,-4805.0 ', 'company1,ZZZ,-2576.0 ', 'company1,BBB,1674.0 ', 
       'company1,CCC,3600.0 ', 'company1,DDD,1743.998 ']
#Create an OrderedDict, this will ensure that the Order in the original
# List is maintained
out_dict = OrderedDict()
#Create a Dictionary out of the first List, Note the key is
#the company and product ID
for e in lst1:
    key, _, value = e.strip().rpartition(",")
    out_dict[key] = float(value)
#Now iterate through the next list
for e in lst2:
# Partition on company, productID and Value
    key, _, value = e.strip().rpartition(",")
#Retrieve the value with the key with default '0'
#and add value from the new list
    out_dict[key] = out_dict.get(key, 0) + float(value)
#Finally recreate the list from the dictionary
lst3 = [','.join(map(str, e)) for e in out_dict.iteritems()]
print lst3

Upvotes: 0

Cameron Sparr
Cameron Sparr

Reputation: 3981

You should be using a dictionary mapping strings to floats like so:

dict1 = {'company1,AAA':7381.0, 'company1,BBB':-8333.0, 'company1,CCC':3079.999}

then when you get a new dict:

dict2 = {'company1,AAA':-4805.0}

you can just say:

for key in dict2.keys():
    dict1[key] = dict1[key] + dict2[key]

or something along these lines (also see function .update())

EDIT:

the .update() function will also allow you to update your dictionary with new items from dict2, using just a simple if statement checking if the key from dict2 is not already in dict1

Upvotes: 1

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