使用Spark Databricks平台从URL读取数据 [英] reading data from URL using spark databricks platform

问题描述

尝试在Databricks社区版平台上使用Spark从url读取数据 我尝试使用spark.read.csv和SparkFiles，但仍然缺少一些简单的要点

trying to read data from url using spark on databricks community edition platform i tried to use spark.read.csv and using SparkFiles but still, i am missing some simple point

url = "https://raw.githubusercontent.com/thomaspernet/data_csv_r/master/data/adult.csv"
from pyspark import SparkFiles
spark.sparkContext.addFile(url)
# sc.addFile(url)
# sqlContext = SQLContext(sc)
# df = sqlContext.read.csv(SparkFiles.get("adult.csv"), header=True, inferSchema= True) 

df = spark.read.csv(SparkFiles.get("adult.csv"), header=True, inferSchema= True)

与路径有关的错误:

Path does not exist: dbfs:/local_disk0/spark-9f23ed57-133e-41d5-91b2-12555d641961/userFiles-d252b3ba-499c-42c9-be48-96358357fb75/adult.csv;'

我也尝试了其他方法

val content = scala.io.Source.fromURL("https://raw.githubusercontent.com/thomaspernet/data_csv_r/master/data/adult.csv").mkString

 # val list = content.split("\n").filter(_ != "")
   val rdd = sc.parallelize(content)
   val df = rdd.toDF

SyntaxError: invalid syntax
  File "<command-332010883169993>", line 16
    val content = scala.io.Source.fromURL("https://raw.githubusercontent.com/thomaspernet/data_csv_r/master/data/adult.csv").mkString
              ^
SyntaxError: invalid syntax

数据应该直接加载到databricks文件夹中，或者我应该能够使用spark.read从URL直接加载，有任何建议

data should be loaded directly to databricks folder or i should be able load directly from url using spark.read, any suggestions

推荐答案

尝试一下.

url = "https://raw.githubusercontent.com/thomaspernet/data_csv_r/master/data/adult.csv"
from pyspark import SparkFiles
spark.sparkContext.addFile(url)

**df = spark.read.csv("file://"+SparkFiles.get("adult.csv"), header=True, inferSchema= True)**

只需获取csv网址的几列.

Just fetching few columns of your csv url.

df.select("age","workclass","fnlwgt","education").show(10);
>>> df.select("age","workclass","fnlwgt","education").show(10);
+---+----------------+------+---------+
|age|       workclass|fnlwgt|education|
+---+----------------+------+---------+
| 39|       State-gov| 77516|Bachelors|
| 50|Self-emp-not-inc| 83311|Bachelors|
| 38|         Private|215646|  HS-grad|
| 53|         Private|234721|     11th|
| 28|         Private|338409|Bachelors|
| 37|         Private|284582|  Masters|
| 49|         Private|160187|      9th|
| 52|Self-emp-not-inc|209642|  HS-grad|
| 31|         Private| 45781|  Masters|
| 42|         Private|159449|Bachelors|
+---+----------------+------+---------+

SparkFiles获取驱动程序或工作程序本地文件的绝对路径.这就是为什么它找不到它的原因.

SparkFiles get the absolute path of the file which is local to your driver or worker. That's the reason why it was not able to find it.

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