Question

I have a piece of code

# create list of (val, key) tuple pairs
freq_list2 = [(val, key) for key, val in freq_dic.items()]
# sort by val or frequency
freq_list2.sort(reverse=True)
freq_list3 = list(freq_list2)
# display result as top 10 most frequent words
for freq, word in freq_list2:
    print word, freq
freq_list4 =[]
freq_list4=freq_list3[:10]

print freq_list4

f = open("wordfreq.txt", "w")
f.write( str(freq_list4) )
f.close()

output_filename = 'wordfreq.arff'
with open(output_filename,"w") as fp:
        fp.write('''@RELATION wordfrequency

@ATTRIBUTE word string
@ATTRIBUTE frequency numeric

@DATA
''')

Essentially I am trying to feed the values from key and val so that @data looks like:

@data
word1, 21
word2, 17

I’m not very good with this particular area, so any help would really be appreciated.

Answer 1

1) You should begin to do

print freq_dic.items()

to see the result and conclude on the utility of the first instruction.

2) What’s the point of freq_list3 ? freq_list3 and freq_list2 are two distinct objects with the same value. Do you need two objects (that is to say their adresses are different: id(freq_list3)==id(freq_list2) is False) of the same value ?

3)

freq_list4 =[]
freq_list4=freq_list3[:10]

freq_list4 =[]
is a useless instuction, since freq_list4 is then re-assign to another object of value freq_list3[:10]

4) If yoiu want to record values of the tuples in a file, you must read these values in the list, that is to say to extract them from the list,

freq_list4[0] is the first tuple in freq_list4

freq_list4[0][0] is the first element of the first tuple in freq_list4
freq_list4[0][1] is the second element of the first tuple in freq_list4

If you iterate on the list:

for item in freq_list4:
    print item[0]
    print item[1]

or

for k,v in freq_list4:
print k
print v