使用pyspark计算所有可能的词对 [英] Counting all possible word pairs using pyspark

问题描述

我有一个文本文档.我需要找到整个文档中重复单词对的可能计数.例如，我有以下 word 文档.该文档有两行，每行以;"分隔.文档:

I have a text document. I need to find the possible counts of repeating word pairs in the overall document. For example, I have the below word document. The document has two lines, each line separated by ';'. Document:

My name is Sam My name is Sam My name is Sam;
My name is Sam;

我正在研究对词计数.预期结果是:

I am working on pairwords count.The expected out is:

[(('my', 'my'), 3), (('name', 'is'), 7), (('is', 'name'), 3), (('sam', 'sam'), 3), (('my', 'name'), 7), (('name', 'sam'), 7), (('is', 'my'), 3), (('sam', 'is'), 3), (('my', 'sam'), 7), (('name', 'name'), 3), (('is', 'is'), 3), (('sam', 'my'), 3), (('my', 'is'), 7), (('name', 'my'), 3), (('is', 'sam'), 7), (('sam', 'name'), 3)]

如果我使用:

wordPairCount = rddData.map(lambda line: line.split()).flatMap(lambda x: [((x[i], x[i + 1]), 1) for i in range(0, len(x) - 1)]).reduceByKey(lambda a,b:a + b)

我得到了连续单词的成对单词及其重复出现次数.

I get pair-words of consecutive words and their count of re-occurences.

如何将每个单词与该行中的每个其他单词配对，然后在所有行中搜索相同的对?

How can I pair each word with every other word in the line and then search for the same pair in all lines?

有人可以看看吗?谢谢

推荐答案

您的输入字符串:

# spark is SparkSession object
s1 = 'The Adventure of the Blue Carbuncle The Adventure of the Blue Carbuncle The Adventure of the Blue Carbuncle; The Adventure of the Blue Carbuncle;'

# Split the string on ; and I parallelize it to make an rdd
rddData = spark.sparkContext.parallelize(rdd_Data.split(";"))

rddData.collect()
# ['The Adventure of the Blue Carbuncle The Adventure of the Blue Carbuncle The Adventure of the Blue Carbuncle', ' The Adventure of the Blue Carbuncle', '']

import itertools

final = (
    rddData.filter(lambda x: x != "")
        .map(lambda x: x.split(" "))
        .flatMap(lambda x: itertools.combinations(x, 2))
        .filter(lambda x: x[0] != "")
        .map(lambda x: (x, 1))
        .reduceByKey(lambda x, y: x + y).collect()
)
# [(('The', 'of'), 7), (('The', 'Blue'), 7), (('The', 'Carbuncle'), 7), (('Adventure', 'the'), 7), (('Adventure', 'Adventure'), 3), (('of', 'The'), 3), (('the', 'Adventure'), 3), (('the', 'the'), 3), (('Blue', 'The'), 3), (('Carbuncle', 'The'), 3), (('Adventure', 'The'), 3), (('of', 'the'), 7), (('of', 'Adventure'), 3), (('the', 'The'), 3), (('Blue', 'Adventure'), 3), (('Blue', 'the'), 3), (('Carbuncle', 'Adventure'), 3), (('Carbuncle', 'the'), 3), (('The', 'The'), 3), (('of', 'Blue'), 7), (('of', 'Carbuncle'), 7), (('of', 'of'), 3), (('Blue', 'Carbuncle'), 7), (('Blue', 'of'), 3), (('Blue', 'Blue'), 3), (('Carbuncle', 'of'), 3), (('Carbuncle', 'Blue'), 3), (('Carbuncle', 'Carbuncle'), 3), (('The', 'Adventure'), 7), (('The', 'the'), 7), (('Adventure', 'of'), 7), (('Adventure', 'Blue'), 7), (('Adventure', 'Carbuncle'), 7), (('the', 'Blue'), 7), (('the', 'Carbuncle'), 7), (('the', 'of'), 3)]

1. 从第一个拆分中删除所有空格
2. Split x 是一个空格分隔的字符串，按空格
3. 使用 itertools.combinations 创建 2 个元素的组合(flatMap 用于将每个单词与行中的每个其他单词配对)
4. 像统计字数一样映射和减少

1. Remove any blank spaces from the first split
2. Split x which is a space divided string, by space
3. Create combinations of 2 elements each using itertools.combinations (flatMap for pair each word with every other word in the line)
4. Map and reduce like you would do for a word-count

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