from pyspark.sql import SparkSession # 初始化 SparkSession spark = SparkSession.builder.appName("RenameColumnExample").getOrCreate() # 创建一个示例 DataFrame data = [("Alice", 29), ("Bob", 34)] columns = ["Name", "Age"] df = spark.createDataFrame(data, columns) # 修改列名 df_ren...
# DataFrame Example 1 columns = ["name","languagesAtSchool","currentState"] df=spark.createDataFrame(data) df.printSchema() df.show() collData=df.collect() print(collData) for row in collData: print( + "," +str(row.lang)) 1. 2. 3. 4. 5. 6. 7. 8. 9. # DataFrame Example...
选项4. 使用sqlContext.sql,它允许您在注册为表的DataFrames sqlContext.registerDataFrameAsTable(data, "myTable") df2 = sqlContext.sql("SELECT Name AS name, askdaosdka as age from myTable") df2.show() # Output #+---+---+ #| name|age| #+---+---+ #|Alberto| 2| #| Dakota| 2...
In PySpark, columns can be renamed using thewithColumnRenamedmethod on a DataFrame. This method takes two arguments: the current column name and the new column name. Here is an example of how to rename a column from “age” to “new_age”: df.withColumnRenamed("age","new_age").show()...
spark dataframe是immutable, 因此每次返回的都是一个新的dataframe (1)列操作 # add a new column data = data.withColumn("newCol",df.oldCol+1) # replace the old column data = data.withColumn("oldCol",newCol) # rename the column data.withColumnRenamed("oldName","newName") # change column ...
rename列名 df.withColumnRenamed("gender","sex").show(truncate=False) 删除列 df4.drop("CopiedColumn").show(truncate=False) 4、where() & filter() where和filter函数是相同的操作,对DataFrame的列元素进行筛选。 import pyspark from pyspark.sql import SparkSession from pyspark.sql.types import StructT...
PySpark Dataframe Basic Operations PySpark Dataframe Schema PySpark Dataframe Add Columns PySpark Dataframe Modify Columns PySpark Dataframe Rename Columns PySpark Dataframe Drop Columns PySpark Dataframe Partitions-Part 1 PySpark Dataframe Partitions-Part 2 PySpark Dataframe Caching PySpark Dataframe...
Some DataFrames have hundreds or thousands of columns, so it's important to know how to rename all the columns programatically with a loop, followed by aselect. Remove dots from all column names Create a DataFrame with dots in the column names: ...
DataFrame 结构使用说明 读取本地文件 查看DataFrame 结构 自定义 schema 选择过滤数据 提取数据 Row & Column 原始sql 查询语句 pyspark.sql.function 示例 背景 PySpark 通过 RPC server 来和底层的 Spark 做交互,通过 Py4j 来实现利用 API 调用Spark 核心。 Spark (written in Scala) 速度比 Hadoop 快很多。Spar...
...PySpark StructType 和 StructField 类用于以编程方式指定 DataFrame 的schema并创建复杂的列,如嵌套结构、数组和映射列。...StructType对象结构 在处理 DataFrame 时,我们经常需要使用嵌套的结构列,这可以使用 StructType 来定义。...下面学习如何将列从一个结构复制到另一个结构并添加新列。PySpark Column 类还...