Spark read parquet with unnamed index

[Lord, Jesse]

When reading a parquet created from a pandas dataframe with an unnamed index 
spark creates a column named “__index_level_0__” since spark DataFrames do not 
support row indexing. This looks like it is probably a bug to me, since as a 
spark user I would expect unnamed index columns to be dropped on read, but 
might be intended.

import pandas as pd
from pyspark.sql import SparkSession
spark = SparkSession.builder.getOrCreate()
pandas_frame = pd.DataFrame({'str_col': ['a', 'b'], 'num_col':[1, 2]})
pandas_frame.to_parquet('test.parquet')
spark_frame = spark.read.parquet('test.parquet')
spark_frame.show()

+-------+-------+-----------------+
|num_col|str_col|__index_level_0__|
+-------+-------+-----------------+
|      1|      a|                0|
|      2|      b|                1|
+-------+-------+-----------------+

Thanks,
Jesse