How to save a spark dataframe to csv on HDFS?

Question

Spark version: 1.6.1, I use pyspark API.

DataFrame: df, which has two colume.

I have tried:

1: df.write.format('csv').save("hdfs://path/bdt_sum_vol.csv")
2: df.write.save('hdfs://path/bdt_sum_vol.csv', format='csv', mode='append')
3: df.coalesce(1).write.format('com.databricks.spark.csv').options(header='true').save('hdfs://path/')
4: df.write.format('com.databricks.spark.csv').save('hdfs://path/df.csv')

(All above didn't work, Failed to find data source)

or:

def toCSVLine(data):
    return ','.join(str(d) for d in data)

lines = df.rdd.map(toCSVLine)
lines.saveAsTextFile('hdfs://path/df.csv')  

(Permission denied)

Q:

1, How to solve "Failed to find data source"?

2, I used sudo to make the dictionary "/path" on hdfs, if I turn the dataframe to rdd, how to write the rdd to csv on hdfs?

Thanks a lot!

Solution

You could try to change ".save" to ".csv":

df.coalesce(1).write.mode('overwrite').option('header','true').csv('hdfs://path/df.csv')