piplinedRDD can't convert to dataframe using toDF - dictionary

Question

I have a pyspark dataframe contains rows of data seperated by comma. I want to split each row and apply LabeledPoints method to it. Then covnert it to dataframe.
Here is my code
import os.path
from pyspark.mllib.regression import LabeledPoint
import numpy as np
file_name = os.path.join('databricks-datasets', 'cs190', 'data-001', 'millionsong.txt')
raw_data_df = sqlContext.read.load(file_name, 'text')
rdd = raw_data_df.rdd.map(lambda line: line.split(',')).map(lambda seq:LabeledPoints(seq[0],seq[1:])).toDF()
It gives the following error message after apply .DF().
---------------------------------------------------------------------------
org.apache.spark.SparkException: Job aborted due to stage failure: Task 0 in stage 38.0 failed 1 times, most recent failure: Lost task 0.0 in stage 38.0 (TID 44, localhost): org.apache.spark.api.python.PythonException: Traceback (most recent call last):
Py4JJavaError Traceback (most recent call last)
<ipython-input-65-dc4d86a8ee45> in <module>()
----> 1 rdd = raw_data_df.rdd.map(lambda line: line.split(',')).map(lambda seq:LabeledPoints(seq[0],seq[1:])).toDF()
2 print(type(rdd))
3 #print(rdd.take(5))
/databricks/spark/python/pyspark/sql/context.py in toDF(self, schema, sampleRatio)
62 [Row(name=u'Alice', age=1)]
63 """
---> 64 return sqlContext.createDataFrame(self, schema, sampleRatio)
65
66 RDD.toDF = toDF
/databricks/spark/python/pyspark/sql/context.py in createDataFrame(self, data, schema, samplingRatio)
421
422 if isinstance(data, RDD):
--> 423 rdd, schema = self._createFromRDD(data, schema, samplingRatio)
424 else:
425 rdd, schema = self._createFromLocal(data, schema)
/databricks/spark/python/pyspark/sql/context.py in _createFromRDD(self, rdd, schema, samplingRatio)

Answer 1

Answer found:
rdd = raw_data_df.map(lambda row: row['value'].split(',')).map(lambda seq:LabeledPoint(float(seq[0]),seq[1:])).toDF()
Here, I need to specifically reference each line of text using row['value'], even though there is only one feature in the row.