Question

我想通过mrjob在列表中找到最大值。当我运行它时，它总是显示错误：

未找到配置；退回到自动配置；没有为内嵌运行器指定配置

我想知道什么意思

class MRWordCounter(MRJob):

def mapper(self, key, line):
            num = csv_readline(line)
            yield num, 1
def reducer(self, word, compare):
            num_list = []
            for value in compare:
                    if value == max(compare):
                            value=num_list
                            yield word, num_list

Answer 1

您可以改用此方法：-

#The most occurred word
#Import Dependencies
from mrjob.job import MRJob
from mrjob.step import MRStep
import re

WORD_RE = re.compile(r"[\w']+")


class MRMostUsedWord(MRJob):

    def mapper_get_words(self, _, line):
        # yield each word in the line
        for word in WORD_RE.findall(line):
            yield (word.lower(), 1)

    def combiner_count_words(self, word, counts):
        # sum the words we've seen so far
        yield (word, sum(counts))

    def reducer_count_words(self, word, counts):
        # send all (num_occurrences, word) pairs to the same reducer.
        # num_occurrences is so we can easily use Python's max() function.
        yield None, (sum(counts), word)

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

    def steps(self):
        return [
            MRStep(mapper=self.mapper_get_words,
                   combiner=self.combiner_count_words,
                   reducer=self.reducer_count_words),
            MRStep(reducer=self.reducer_find_max_word)
        ]


if __name__ == '__main__':
    MRMostUsedWord.run()

它的作用是：-

映射单词。
结合每个单词的计数。
翻转键值对。
减少找到出现的最大单词的数量。
要运行代码，

将文本文件和python脚本保存在同一文件夹中，然后：

python3 xyz.py xyz.txt

python通过mrjob找到最大值

1 个答案: