根据子列表的前两项过滤列表列表-使用NLTK进行自然语言处理

Question

I have generated a list of trigrams and their frequencies in NLTK with this code

tokens = nltk.wordpunct_tokenize(docs)
from nltk.collocations import *
trigram_measures = nltk.collocations.TrigramAssocMeasures()
finderT = TrigramCollocationFinder.from_words(tokens)
scoredT = finderT.score_ngrams(trigram_measures.raw_freq)

Given a user defined 'input' of two words, I want to filer the list scoredT to return those values where the input matches the first two items of the sub list in scoredT

scoredT looks like this

[(('out', 'to', 'the'), 2.7147650642313413e-05),
(('proud', 'of', 'you'), 2.7147650642313413e-05)]

So if input were equal to 'out to', Id like to filter the list to return 'the'

I tried

matches = filter(scoredT[0:len(scoredT)][0:1]==input, scoredT)

but get the following error TypeError: 'bool' object is not callable

Answer 1

scoredT[0:len(scoredT)][0:1]==input compares the first element of scoredT to input . So it will be boolean. Then you pass it to filter , which requires the first argument to be a boolean valued function , hence your error. The pythonic way:

matches = [(trigram, score) for (trigram, score) in scoredT if trigram[:2] == input]

Also you need to make sure that input is a tuple.