ValueError: RDD is empty-- Pyspark (Windows Standalone)

Question

I am trying to create an RDD but spark not creating it, throwing back error, pasted below;

data = records.map(lambda r: LabeledPoint(extract_label(r), extract_features(r)))
first_point = data.first()

Py4JJavaError                             Traceback (most recent call last)
<ipython-input-19-d713906000f8> in <module>()
----> 1 first_point = data.first()
  2 print "Raw data: " + str(first[2:])
  3 print "Label: " + str(first_point.label)
  4 print "Linear Model feature vector:\n" + str(first_point.features)
  5 print "Linear Model feature vector length: " + str(len    (first_point.features))

C:\spark\python\pyspark\rdd.pyc in first(self)
1313         ValueError: RDD is empty
1314         """
-> 1315         rs = self.take(1)
1316         if rs:
1317             return rs[0]

C:\spark\python\pyspark\rdd.pyc in take(self, num)
 1295 
 1296             p = range(partsScanned, min(partsScanned + numPartsToTry, totalParts))
-> 1297             res = self.context.runJob(self, takeUpToNumLeft, p)..................

Any help will be greatly appreciated.

Thank you, Innocent

Answer 1

Your records is empty. You could verify by calling records.first().

Calling first on an empty RDD raises error, but not collect. For example,

records = sc.parallelize([])

records.map(lambda x: x).collect()

[]

records.map(lambda x: x).first()

ValueError: RDD is empty

Answer 2

I was also facing this issue, with the FIRST() action method, I checked and found that RDD is empty hence I was getting this issue. Make sure RDD has at least one record to process.