python - Python mrjob - 找到 10 个最长的单词，但 mrjob 返回重复的单词

Question

我正在使用 Python mrjob 从文本文件中查找 10 个最长的单词。我得到了一个结果，但结果包含重复的单词。我如何只获得唯一的单词（即删除重复的单词）？

%%file most_chars.py  
from mrjob.job import MRJob
from mrjob.step import MRStep
import re

WORD_RE = re.compile(r"[\w']+") # any whitespace or apostrophe, used to split lines below


class MostChars(MRJob):
    def steps(self):
        return [
            MRStep(mapper=self.mapper_get_words,
                  reducer=self.reducer_find_longest_words)
        ]

    def mapper_get_words(self, _, line):
        for word in WORD_RE.findall(line):   
            yield None, (len(word), word.lower().strip())

    # discard the key; it is just None
    def reducer_find_longest_words(self, _, word_count_pairs):
        # each item of word_count_pairs is (count, word),
        # so yielding one results in key=counts, value=word

        sorted_pair = sorted(word_count_pairs, reverse=True)
        
        for pair in sorted_pair[0:10]:
            yield pair
              
if __name__ == '__main__':
    MostChars.run()

实际输出：

18  "overcapitalization"
18  "overcapitalization"
18  "overcapitalization"
17  "uncomprehendingly"
17  "misunderstandings"
17  "disinterestedness"
17  "disinterestedness"
17  "disinterestedness"
17  "disinterestedness"
17  "conventionalities"

预期输出：

18  "overcapitalization"
17  "uncomprehendingly"
17  "misunderstandings"
17  "disinterestedness"
17  "conventionalities"

和另外 5 个独特的词

标签： pythonmrjob

Answer 1

更新reducer_find_longest_words以仅获取唯一元素。注意使用list(set()).

    def reducer_find_longest_words(self, _, word_count_pairs):
        # each item of word_count_pairs is (count, word),
        # so yielding one results in key=counts, value=word

        unique_pairs = [list(x) for x in set(tuple(x) for x in word_count_pairs)]
        sorted_pair = sorted(unique_pairs, reverse=True)
        
        for pair in sorted_pair[0:10]:
            yield pair