编写一个地图诱导程序,该程序将包含逗号分离单词和输出的 CSV 文件作为输入,每个单词的行都显示在单词中。
例如:
goat,chicken,horse
cat,horse
dog,cat,sheep
buffalo,dolphin,cat
sheep
相应的输出如下:
"buffalo" ["buffalo,dolphin,cat"]
"cat" ["buffalo,dolphin,cat", "cat,horse", "dog,cat,sheep"]
"chicken" ["goat,chicken,horse"]
"dog" ["dog,cat,sheep"]
"dolphin" ["buffalo,dolphin,cat"]
"goat" ["goat,chicken,horse"]
"horse" ["cat,horse", "goat,chicken,horse"]
"sheep" ["dog,cat,sheep", "sheep"]
代码没写完,思路如下:
from mrjob.job import MRJob
from mrjob.step import MRStep
import csv
class part2(MRJob):
def steps(self):
return [MRStep(mapper=self.mapper, reducer=self.reducer)]
#return [MRStep(mapper=self.mapper)]
def mapper(self, key, document):
for word in document.split(','):
yield word, 1
def reducer(self, word, line):
yield word, line
part2.run()
from mrjob.job import MRJob
class FrequencyCount(MRJob):
def mapper(self, _, line):
words = line.split(',')
for word in words:
yield (word, line)
def reducer(self, key, values):
lines = []
for line in values:
lines.append(line)
yield key, lines
if __name__ == '__main__':
FrequencyCount.run()
亲测有效~~如果有其他问题,欢迎私信与我交流~
如果问题得到解决,要记得采纳一手呀~
比较疑惑已创建的csv文看作一个数组吗?那我这里把单个单词作为键值映射可以吗?因为它要求同时输出单词和所在行。我还有个疑问就是,用行号的话,是把行还是单词看作一个值?如果要把行看作一个值的话是不是得的把行映射进去还是单独在reduce函数里操作