c.toLowerCase().replaceAll("\\.","_") +"_new" 转自:https://kontext.tech/column/spark/527/scala-change-data-frame-column-names-in-spark
评估条件列表并返回多个可能的结果表达式之一。如果不调用Column.otherwise(),则不匹配条件返回None 参数:condition – 一个布尔的列表达式.value – 一个文字值或一个Column表达式 >>> df.select(when(df['age'] == 2, 3).otherwise(4).alias("age")).collect() [Row(age=3), Row(age=4)] >>> df...
df.rename(columns=lambdax:x+1) # 批量更改列名 df.rename(columns={'old_name':'new_ name'}) # 选择性更改列名 df.set_index('column_one') # 将某个字段设为索引,可接受列表参数,即设置多个索引 df.reset_index("col1") # 将索引设置为col1字段,并将索引新设置为0,1,2... df.rename(index...
# 排序df=df.sort('ts',ascending=False)# 获取最大最小时间戳df.select(F.max(df.ts),F.min(df.ts)).show() 代码语言:python 代码运行次数:0 运行 AI代码解释 # https://www.programiz.com/python-programming/datetime/timestamp-datetime# 转换为日期print("Min date =",datetime.fromtimestamp(15383...
Python frompyspark.sqlimportSparkSession spark = SparkSession.builder.getOrCreate()# Read clickstream_data from storage pool HDFS into a Spark data frame. Applies column renames.df = spark.read.option("inferSchema","true").csv('/securelake/landing/criteo/test.txt', sep='\t', header=False)...
Select column Choose one or more columns to keep, and delete the rest Rename column Rename a column Drop missing values Remove rows with missing values Drop duplicate rows Drop all rows that have duplicate values in one or more columns Fill missing values Replace cells with missing values with...
至于其他查询并不支持分布式执行,包括 SELECT、CREATE、DROP、RENAME 和 ATTACH。例如,为了创建多个副本,我们需要分别登录每个 ClickHouse 节点,在它们本地执行各自的 CREATE 语句(后面将会介绍如何利用集器配置简化这一操作)。接下来,会依次介绍上述流程的工作机理。为了便于理解,我们先来整体认识一下各个流程的介绍方法...
python sqlite 获取表名、表 data.sqlite') # 链接数据库 cur = mydb.cursor() # 创建游标cur来执行SQL语句 # 获取表名...# Tables 为元组列表 print Tables tbl_name = Tables[0][0] # 获取第一个表名...# 获取表的列名 cur.execute("SELECT * FROM {}".format(tbl_name)) col_name_list =...
Python #PyPIpip install spark-nlp==6.0.0 Spark Packages spark-nlpon Apache Spark 3.0.x, 3.1.x, 3.2.x, 3.3.x, and 3.4.x (Scala 2.12): spark-shell --packages com.johnsnowlabs.nlp:spark-nlp_2.12:6.0.0 pyspark --packages com.johnsnowlabs.nlp:spark-nlp_... ...
// rename a column tdf = tdf.withColumnRenamed("VendorID", "vendor_id") // filter anomalous values df = df.filter($"fare_amount" > 0 and $"fare_amount" < 100) df = df.filter($"trip_distance" > 0 and $"trip_distance" < 100) ...