pythonmappermrjob

my code is outputting a tuple of values and I would like it to be in individual pairs, i need help to understand how to modify it


def mapper(self, _, line):
    stop_words = set(["to", "a", "an", "the", "for", "in", "on", "of", "at", "over", "with", "after", "and", "from", "new", "us", "by", "as", "man", "up", "says", "in", "out", "is", "be", "are", "not", "pm", "am", "off", "more", "less", "no", "how"])
    (date,words) = line.strip().split(",")

    word_list = words.split()
    clean_words = [word for word in word_list if word not in stop_words]
    clean_words.sort()


    yield (date[0:4],clean_words)

This is in a MRJob mapper. Current output looks like

"2003" ["word 1","word 2", "word 3", "word 4"]
"2004" ["word 1","word 2", "word 3", "word 4"]

What I would like it to be is:

"2003" "Word 1"
"2003" "Word 2"
"2004" "Word 3"
"2004" "Word 4"

Once it is output like this i can send to the reducer to perform a count on the year and top3 words


Solution

  • Use a loop to yield each word separately.

    def mapper(self, _, line):
        stop_words = set(["to", "a", "an", "the", "for", "in", "on", "of", "at", "over", "with", "after", "and", "from", "new", "us", "by", "as", "man", "up", "says", "in", "out", "is", "be", "are", "not", "pm", "am", "off", "more", "less", "no", "how"])
        (date,words) = line.strip().split(",")
    
        word_list = words.split()
        clean_words = [word for word in word_list if word not in stop_words]
        clean_words.sort()
    
        for word in clean_words:
            yield (date[0:4],word)