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Pyspark替换Spark数据帧列中的字符串

[英]Pyspark replace strings in Spark dataframe column

I'd like to perform some basic stemming on a Spark Dataframe column by replacing substrings. 我想通过替换子字符串在Spark Dataframe列上执行一些基本的词干。 What's the quickest way to do this? 最快的方法是什么?

In my current use case, I have a list of addresses that I want to normalize. 在我目前的用例中,我有一个我想要规范化的地址列表。 For example this dataframe: 例如,这个数据帧:

id     address
1       2 foo lane
2       10 bar lane
3       24 pants ln

Would become 会成为

id     address
1       2 foo ln
2       10 bar ln
3       24 pants ln

For Spark 1.5 or later, you can use the functions package: 对于Spark 1.5或更高版本,您可以使用函数包:

from pyspark.sql.functions import *
newDf = df.withColumn('address', regexp_replace('address', 'lane', 'ln'))

Quick explanation: 快速解释:

  • The function withColumn is called to add (or replace, if the name exists) a column to the data frame. 调用函数withColumn以向数据框添加(或替换,如果名称存在)列。
  • The function regexp_replace will generate a new column by replacing all substrings that match the pattern. 函数regexp_replace将通过替换与模式匹配的所有子字符串来生成新列。

For scala 对于斯卡拉

import org.apache.spark.sql.functions.regexp_replace
import org.apache.spark.sql.functions.col
data.withColumn("addr_new", regexp_replace(col("addr_line"), "\\*", ""))

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