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

Question

def sentiment(text)
    ................//some code   
    pos=round(pos,3)
    neu=round(neu,3)
    neg=round(neg,3)

    result={'pos':[pos] , 'neg':[neg],'neu':[neu] }
    return result    

count=0;

f1 = open('testData.txt')

sentence= f1.readline()

result={'pos':[] , 'neg':[],'neu':[] }

for sentence in f1:
    vs =sentiment(sentence)
    result['pos'].append(vs['pos'])
    result['neg'].append(vs['neg'])
    result['neu'].append(vs['neu'])
    sentence=f1.readline()
    print ('sum:')

for i in result.keys():
    print ('\t',i, '=>', sum(result[i]))

I got an error

Traceback (most recent call last):
  File "C:\Users\DIl\Desktop\MYChoi\lex\sentiment_lexian.py", line 305, in <module>
    print ('\t',i, '=>', sum(result[i]))
TypeError: unsupported operand type(s) for +: 'int' and 'list'

Answer 1

The default for sum() is 0 -- it's meant for adding up numbers. However, you have given it a list of list s instead:

# 'pos' maps to a list with a single number in it
result = {'pos':[pos], 'neg':[neg], 'neu':[neu]}

# everytime this runs, 'pos' gets a new list
result['pos'].append(vs['pos'])

# i == 'pos'
# result[i] == [[0.827], [0.273], [0.111]] (for example)
for i in result.keys():
    print ('\t',i, '=>', sum(result[i]))

If you change the line in sentiment from

result = {'pos':[pos], 'neg':[neg], 'neu':[neu]}

to

result = {'pos':pos, 'neg':neg, 'neu':neu}

then that should do what you want, if pos , neg , and neu are single numbers.