返回文本的FRES（Flesch阅读 - 缓和测试）

Question

我正在尝试使用此wiki中的公式来实现一个返回文本的Flesch-Kincaid可读性测试的python函数：Flesch reading-ease test

我也遇到了一个与我所做的回答相同的问题：Converting Readability formula into python function

因此，通过使用此作为一种指南，我对我的实现采取了类似的方法，并以此作为我的代码结束：

import nltk
import collections
nltk.download('punkt')
nltk.download('gutenberg')
nltk.download('brown')

# DO NOT MODIFY THE CODE BELOW #
import re
VC = re.compile('[aeiou]+[^aeiou]+', re.I)
def count_syllables(word):
    return len(VC.findall(word))

def compute_fres(text):
    """Return the FRES of a text.
    >>> emma = nltk.corpus.gutenberg.raw('austen-emma.txt')
    >>> compute_fres(emma) # doctest: +ELLIPSIS
    99.40...
    """

    tToken = nltk.word_tokenize(text)

    for f in nltk.corpus.gutenberg.fileids():
        nsents = len(nltk.corpus.gutenberg.sents(f))
        nwords = len(nltk.corpus.gutenberg.words(f))
        nsyllables = sum(count_syllables(w) for w in words)
        fres = 206.835 - 1.015 * (nwords / nsents) - 84.6 * (nsyllables / nwords)
    return len(fres.findall(tToken))

然后我运行了我的代码并收到了此错误消息：

Error
**********************************************************************
File "C:/Users/WORLD/PycharmProjects/a1/a1.py", line 54, in a1.compute_fres
Failed example:
    compute_fres(emma) # doctest: +ELLIPSIS
Exception raised:
    Traceback (most recent call last):
      File "C:\Program Files\JetBrains\PyCharm Community Edition 2017.3.4\helpers\pycharm\docrunner.py", line 140, in __run
        compileflags, 1), test.globs)
      File "<doctest a1.compute_fres[1]>", line 1, in <module>
        compute_fres(emma) # doctest: +ELLIPSIS
      File "C:/Users/WORLD/PycharmProjects/a1/a1.py", line 63, in compute_fres
        nsyllables = sum(count_syllables(w) for w in words)
    NameError: name 'words' is not defined

与其他用户的帖子一样，我的目标是通过实现正确的功能来传递doctest。我也可以假设他/她与我在同一个编程班。

我对python有点新意，所以我不确定我做错了什么。