Python列表理解“太多值无法解包”

Question

对于这个问题很抱歉，但是我为错误“无法解开太多值”而疯狂。 这是代码

FREQ = 3
fourgrams=""
n = 4
tokens = token_text(text) # is a function that tokenize
fourgrams = ngrams(tokens, n)
final_list = [(item,v) for item,v in nltk.FreqDist(fourgrams) if v > FREQ]
print final_list

错误在哪里？ 非常感谢

Answer 1

FreqDist是类似字典的对象。 迭代产生键（不是键值对）。 如果要迭代两个键值对，请使用FreqDist.items或FreqDist.iteritems ：

final_list = [(item,v) for item,v in nltk.FreqDist(fourgrams).items() if v > FREQ]

Answer 2

看看这个：

from collections import Counter

from nltk.corpus import brown
from nltk.util import ngrams

# Let's take the first 10000 words from the brown corpus
text = brown.words()[:10000]
# Extract the ngrams
bigrams = ngrams(text, 2)
# Alternatively, unstead of a FreqDist, you can simply use collections.Counter
freqdist = Counter(bigrams)
print len(freqdist)
# Gets the top 5 ngrams
top5 = freqdist.most_common()[:5]
print top5
# Limits v > 10
freqdist = {k:v for k,v in freqdist.iteritems() if v > 10}
print len(freqdist)

[出]：

7615
[(('of', 'the'), 95), (('.', 'The'), 76), (('in', 'the'), 59), (("''", '.'), 40), ((',', 'the'), 36)]
34