Python printing to a file. Sorting with defaultdict

Question

I have some code:

filename = "training_data.txt"
with open(filename,'r') as infile:
     d = defaultdict(lambda: defaultdict(int))
     tagRE = re.compile(r'[A-Za-z]+/[A-Z]+')
     for line in infile:
         for token in tagRE.findall(line):
             word, tag = token.split("/")
             d[word][tag] += 1

f = open('out.txt', 'w')           
for word, word_data in d.items():
    f.write(word + " " + " ".join(tag + ":" + str(freq) + '\n'
    for tag, freq in word_data.items()))    

The training data is part-of-speech tagged text e.g.

Today/NN ,/, PC/NN shipments/NNS annually/RB total/VBP some/DT $/$ 38.3/CD billion/CD world-wide/JJ ./.

Text written to the file should be of the format: word: part-of-speech:frequency where if a word has multiple tags, this and the frequency are on the same line. At the moment, the linebreak is putting tags onto a new line if a word has more than one of these. I would like to:

1) Have these on the same line e.g. mean VBP:7 JJ:1 NN:2 VB:27

2) Have these frequencies printed in descending order. Does my data structure allow for this? I can't work out how I would do this.

Thanks!

Answer 1

tagfreq = " ".join(tag + ":" + str(freq) 
           for tag, freq in 
           sorted(word_data.items(), key=lambda x: x[1], reversed=True))
w = ''.join([word, " ",  tagfreq, '\n'])
f.write(w) 

Use join instead of + for strings, generally. moved the \n to the end of the write and sorted items by frequency in descending order.