adding lists with containers

Question

How can I accomplish this in Python? Combining Lists of Word Frequency Data

Let's say I have two lists A and B and both contain the words& frequencies of a file in descending frequency order, how can I do what's done in the question in Python?

from FrequentWords import *
from WordFrequencies import * # makes the list with words&frequencies 
L = WordFrequencies('file.txt')
words1 = L[0]
freqs1 = L[1]
L1 = computeWordFrequencies('file1.txt')
words2 = L1[0]
freqs2 = L1[1]
words = zip(*sorted(zip(L,L1)))
both1 = sorted(freqs1+freqs2,reverse=True)
common_words = set(words1) & set(words2)
frequency_common_words = both1

Are you using lists, dicts, sets, or some other storage system? Can you show an example of your data format? — neilr8133, Mar 08 '13 at 22:48
I've tried sets and zipping. I think I'm approaching it wrong. — user2041448, Mar 08 '13 at 22:59

score 4 · Answer 1 · answered Mar 08 '13 at 22:51

4

I'd use collections.Counter:

>>> from collections import Counter
>>> c = Counter()
>>> a = {'a': 2, 'b': 3}
>>> b = {'b': 3, 'c': 4}
>>> c.update(a)
>>> c.update(b)
>>> c
    Counter({'b': 6, 'c': 4, 'a': 2})

answered Mar 08 '13 at 22:51

Blender

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That's a way better solution than mine. Nice. – Brenden Brown Mar 08 '13 at 22:52
Thank you, but I don't need the frequency, just the word. Plus, my words and frequencies in my Lists are separated into sublists. – user2041448 Mar 08 '13 at 23:02

score 0 · Answer 2 · answered Mar 08 '13 at 22:50

If your starting data is in dictionaries, it's doable:

output_dict = {}
for k, v in first_dict:
    if k in second_dict:
        v = v + second_dict[k]
    output_dict[k] = v

for k, v in second_dict:
    if k not in first_dict:
        output_dict[k] = v

adding lists with containers

2 Answers2