pyspark dataframe Column alias 重命名列(name) df = spark.createDataFrame( [(2, "Alice"), (5, "Bob")], ["age", "name"])df.select(df.age.alias("age2")).show()+---+|age2|+---+| 2|| 5|+---+ astype alias cast 修改列类型 data.schemaStructType([StructField('name', String...
我们可以使用lit函数创建一个固定的数组值,也可以使用其他DataFrame列的值来创建数组。 下面是一个示例代码,演示如何向PySpark DataFrame添加一个数组列: frompyspark.sqlimportSparkSessionfrompyspark.sql.functionsimportcol,lit,array# 创建SparkSessionspark=SparkSession.builder.appName("Add Array Column").getOrCreat...
You shouldn't need to use exlode, that will create a new row for each value in the array. The reason max isn't working for your dataframe is because it is trying to find the max for that column for every row in you dataframe and not just the max in the array. ...
6.Replace Column with Another Column Value #Replace column with another column frompyspark.sql.functionsimportexpr df=spark.createDataFrame( [("ABCDE_XYZ","XYZ","FGH")], ("col1","col2","col3") ) df.withColumn("new_column", expr("regexp_replace(col1, col2, col3)") .alias("replac...
PySpark Replace Column Values in DataFrame Pyspark 字段|列数据[正则]替换 转载:[Reprint]:https://sparkbyexamples.com/pyspark/pyspark-replace-column-values/#:~:text=By using PySpark SQL function regexp_replace () you,value with Road string on address column. 2. ...
PySpark-引用DataFrame中名为“name”的列 我正在尝试使用PySpark解析json数据。下面是脚本。 arrayData = [ {"resource": { "id": "123456789", "name2": "test123" } } ] df = spark.createDataFrame(data=arrayData) df3 = df.select(df.resource.id, df.resource.name2)...
Pyspark DataFrame drop columns问题是指在使用Pyspark进行数据处理时,如何删除DataFrame中的列。 Pyspark是一个用于大规模数据处理的Python库,它提供了丰富的API和功能,可以方便地进行数据清洗、转换和分析。 要删除DataFrame中的列,可以使用drop()方法。该方法接受一个或多个列名作为参数,并返回一个新的DataFrame,其中不...
# subset:指定用于去重的列,列字符串或列list# keep: first代表去重后保存第一次出现的行# inplace: 是否在原有的dataframe基础上修改df.drop_duplicates(subset=None,keep='first',inplace=False) 聚合 pyspark df.groupBy('group_name_c2').agg(F.UserDefinedFunction(lambdaobj:'|'.join(obj))(F.collect...
df=pd.DataFrame(pd.read_excel(excelFile))engine=create_engine('mysql+pymysql://root:123456@localhost:3306/test')df.to_sql(table_name,con=engine,if_exists='replace',index=False) 2.3 读取数据库的数据表 从数据库中读取表数据进行操作~
通过申明schema的方式创建dataframe 在qualification和gender列应用OneHotEncoder 用StringIndex加工qualification列 用StringIndex加工gender列 One hot encoding of a numeric column 使用Pipeline Part1 - StringIndexer 用法 详细内容请见: https://medium.com/@nutanbhogendrasharma/role-of-stringindexer-and-pipelines-in...