You can also replace column values from thepython dictionary (map). In the below example, we replace the string value of thestatecolumn with the full abbreviated name from a dictionarykey-value pair, in order to do so I usePySpark map() transformation to loop through each row of DataFrame....
1、 agg(expers:column*) 返回dataframe类型 ,同数学计算求值 df.agg(max("age"), avg("salary")) df.groupBy().agg(max("age"), avg("salary")) 2、 agg(exprs: Map[String, String]) 返回dataframe类型 ,同数学计算求值 map类型的 df.agg(Map("age" -> "max", "salary" -> "avg")) df....
CodeInText:指示文本中的代码词、数据库表名、文件夹名、文件名、文件扩展名、路径名、虚拟 URL、用户输入和 Twitter 句柄。以下是一个例子:“将下载的WebStorm-10*.dmg磁盘映像文件挂载为系统中的另一个磁盘。” 代码块设置如下: test("Should use immutable DF API") {importspark.sqlContext.implicits._ /...
format(column_name)) -- Example with the column types for column_name, column_type in dataset.dtypes: -- Replace all columns values by "Test" dataset = dataset.withColumn(column_name, F.lit("Test")) 12. Iteration Dictionaries # Define a dictionary my_dictionary = { "dog": "Alice",...
when(condition, value1).otherwise(value2),意为:当满足条件condition的值时赋值为values1,不满足条件的则赋值为values2,otherwise表示,不满足条件的情况下,应该赋值何值。 例: from pyspark.sql import functions as F df.select(df.customerID,F.when(df.gender=="Male","1").when(df.gender=="Female",...
PySpark Replace Column Values in DataFrame PySpark Retrieve DataType & Column Names of DataFrame PySpark Replace Empty Value With None/null on DataFrame PySpark Find Maximum Row per Group in DataFrame PySpark Select First Row of Each Group?
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.select(when(df.age == 2, df.age + 1).alias("age")).collect() [Row(age=3), Ro...
# filter(condition:Column):通过给定条件过滤行。 # count():返回DataFrame行数。 numInstances = int(numChange0/10000)*10000 train = data.filter(data.is_acct_aft==1).sample(False,numInstances/numChange1+0.001).limit(numInstances).unionAll(data.filter(data.is_acct_aft==0).sample(False, 1.0...
To replace strings with other values, use the replace method. In the example below, any empty address strings are replaced with the word UNKNOWN:Python Копирај df_customer_phone_filled = df_customer.na.replace([""], ["UNKNOWN"], subset=["c_phone"]) Append rows...
Fill NULL values in specific columns Fill NULL values with column average Fill NULL values with group average Unpack a DataFrame's JSON column to a new DataFrame Query a JSON column Sorting and Searching Filter a column using a condition Filter based on a specific column value Filter based on...