pyspark在单个加载中加载多个分区文件

时间:2018-01-19 15:38:35

标签: apache-spark pyspark apache-spark-sql orc partitioned-view

我正在尝试在一次加载中加载多个文件。它们都是分区文件 当我尝试使用1个文件时,它可以工作,但是当我列出24个文件时,它给了我这个错误,我找不到任何限制的文档,除了在加载后进行联合之外还有一个解决方法。 还有其他选择吗?

代码下面重新创建问题:

basepath = '/file/' 
paths = ['/file/df201601.orc', '/file/df201602.orc', '/file/df201603.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc',  
         '/file/df201604.orc', '/file/df201605.orc', '/file/df201606.orc', ]   

df = sqlContext.read.format('orc') \
               options(header='true',inferschema='true',basePath=basePath)\
               .load(*paths)

收到错误:

 TypeError                                 Traceback (most recent call last)
 <ipython-input-43-7fb8fade5e19> in <module>()

---> 37 df = sqlContext.read.format('orc')                .options(header='true', inferschema='true',basePath=basePath)                .load(*paths)
     38 

TypeError: load() takes at most 4 arguments (24 given)

1 个答案:

答案 0 :(得分:2)

正如the official documentation中所述,要阅读多个文件,您应该传递list

  

路径 - 可选字符串或文件系统支持的数据源的字符串列表。

所以在你的情况下:

(sqlContext.read
    .format('orc') 
    .options(basePath=basePath)
    .load(path=paths))

只有在使用可变参数定义*时,参数解包(load)才有意义,例如:

def load(this, *paths):
    ...