from pyspark.sql import SparkSession from pyspark.sql.functions import count, col, when # 创建 SparkSession spark = SparkSession.builder.appName("example").getOrCreate() # 示例 DataFrame data = [ ("Alice", 29), ("Bob", 31), ("Alice", 29), ("Charlie", 25) ] columns = ["name"...
| name|CASE WHEN (age >4) THEN1WHEN (age <3
CASE WHEN description LIKE '%love%' THEN 'Love_Theme' \ WHEN description LIKE '%hate%' THEN 'Hate_Theme' \ WHEN description LIKE '%happy%' THEN 'Happiness_Theme' \ WHEN description LIKE '%anger%' THEN 'Anger_Theme' \ WHEN description LIKE '%horror%' THEN 'Horror_Theme' \ WHEN desc...
What functions do you use to implement a case-when statement in Pyspark? when(), else() case(), when() when(), otherwise() if(), else() 第7个问题 What will be the output of the following statement? ceil(2.33, 4.6, 1.09, 10.9) (2, 4, 1, 0) (3, 5, 2, 11) (2.5, 4.5...
本书将帮助您实施一些实用和经过验证的技术,以改进 Apache Spark 中的编程和管理方面。您不仅将学习如何使用 Spark 和 Python API 来创建高性能的大数据分析,还将发现测试、保护和并行化 Spark 作业的技术。 本书涵盖了 PySpark 的安装和设置、RDD 操作、大数据清理和整理,以及将数据聚合和总结为有用报告。您将学习...
1. 查1.1 行元素查询操作 像SQL那样打印列表前20元素,show函数内可用int类型指定要打印的行数:df.show() df.show(30)以树的形式打印概要:df.printSchema()获取头几行到本地:list = df.head(3) # Example: [Row(a=1, b=1), Row(a=2, b=2), ... ...] list = df.take( ...
specifies the behavior of the save operation when data already exists. append: Append contents of this DataFrame to existing data. overwrite: Overwrite existing data. ignore: Silently ignore this operation if data already exists. error (default case): Throw an exception if data already exists. ...
The only argument you need to pass to.cast()is the kind of value you want to create, in string form. For example, to create integers, you'll pass the argument"integer"and for decimal numbers you'll use"double". You can put this call to.cast()inside a call to.withColumn()to overwr...
An Example PySpark Learning Plan Even though each person has their way of learning, it’s always a good idea to have a plan or guide to follow for learning a new tool. We’ve created a potential learning plan outlining where to focus your time and efforts if you’re just starting with...
pyspark-sql-case-when.py PySpark Examples Mar 29, 2021 pyspark-string-date.py PySpark Date Functions Mar 4, 2021 pyspark-string-timestamp.py PySpark Date Functions Mar 4, 2021 pyspark-string-to-array.py PySpark Examples Feb 22, 2021 pyspark-struct-to-map.py PySpark Github Examples Mar 31,...