I have a resulting RDD labelsAndPredictions = testData.map(lambda lp: lp.label).zip(predictions)
. This has output in this format:
[(0.0, 0.08482142857142858), (0.0, 0.11442786069651742),.....]
What I want is to create a CSV file with one column for labels
(the first part of the tuple in above output) and one for predictions
(second part of tuple output). But I don't know how to write to a CSV file in Spark using Python.
How can I create a CSV file with the above output?
Just map
the lines of the RDD (labelsAndPredictions
) into strings (the lines of the CSV) then use rdd.saveAsTextFile()
.
def toCSVLine(data):
return ','.join(str(d) for d in data)
lines = labelsAndPredictions.map(toCSVLine)
lines.saveAsTextFile('hdfs://my-node:9000/tmp/labels-and-predictions.csv')