python nltk — stemming list of sentences/phrases

问题

I have bunch of sentences in a list and I wanted to use nltk library to stem it. I am able to stem one sentence at a time, however I am having issues stemming sentences from a list and joining them back together. Is there a step I am missing? Quite new to nltk library. Thanks!

import nltk 
from nltk.stem import PorterStemmer 
ps = PorterStemmer()

# Success: one sentences at a time 
data = 'the gamers playing games'
words = word_tokenize(data)
for w in words:
    print(ps.stem(w))


# Fails: 

data_list = ['the gamers playing games',
            'higher scores',
            'sports']
words = word_tokenize(data_list)
for w in words:
    print(ps.stem(w))

# Error: TypeError: expected string or bytes-like object
# result should be: 
['the gamer play game',
 'higher score',
 'sport']

回答1:

You're passing a list to word_tokenize which you can't.

The solution is to wrap your logic in another for-loop,

data_list = ['the gamers playing games','higher scores','sports']
for words in data_list:
    words = tokenize.word_tokenize(words)
    for w in words:
        print(ps.stem(w))

>>>>the
gamer
play
game
higher
score
sport

来源：https://stackoverflow.com/questions/51330099/python-nltk-stemming-list-of-sentences-phrases