pyspark使用熊猫读取csv，如何保留标题

Question

我正在使用 pandas 块功能读取 csv。它可以工作，除了我无法保留标题。有没有办法/选项来做到这一点？这是示例代码：

import pyspark
import pandas as pd
sc = pyspark.SparkContext(appName="myAppName")
spark_rdd = sc.emptyRDD()

# filename: csv file
chunks = pd.read_csv(filename, chunksize=10000)
for chunk in chunks:
    spark_rdd +=  sc.parallelize(chunk.values.tolist())

    #print(chunk.head())
    #print(spark_rdd.toDF().show())
    #break

spark_df = spark_rdd.toDF()
spark_df.show()

Answer 1

试试这个：

import pyspark
import pandas as pd
sc = pyspark.SparkContext(appName="myAppName")
spark_rdd = sc.emptyRDD()

# Read ten rows to get column names
x = pd.read_csv(filename,nrows=10)
mycolumns = list(x)

# filename: csv file
chunks = pd.read_csv(filename, chunksize=10000)
for chunk in chunks:
    spark_rdd +=  sc.parallelize(chunk.values.tolist())

spark_df = spark_rdd.map(lambda x:tuple(x)).toDF(mycolumns)
spark_df.show()

Answer 2

我最终使用了 databricks 的 spark-csv

sc = pyspark.SparkContext()
sql = pyspark.SQLContext(sc)

df = sql.read.load(filename, 
                 format='com.databricks.spark.csv', 
                 header='true', 
                 inferSchema='true')